What is claimed: 1. A cabled platform suspension system, said system comprising: a platform including supporting means defining first and second support points at spaced locations along a front work-access edge of the platform and a third, stabilizing/rotator support point; a support structure for the platform defining first, second, third and fourth suspension points arranged in a substantially rectangular pattern and from which said platform is suspended; and at least six cables connected between said platform and said support structure, said six cables comprising: first and second cables respectively connected between said first and fourth suspension points and said first and second support points on said platform; third and fourth cables respectively connected between said second and third suspension points and said first and second support points on said platform; and fifth and sixth cables respectively connected between said second and third suspension points and said third support point on said platform. 2. A cabled platform suspension system according to claim 1 wherein said platform includes first and second laterally and oppositely extending support members and said first and second support points are located at respective distal ends of said support members. 3. A cabled platform suspension system according to claim 2 wherein said platform further includes a rearwardly extending support member having a distal end and said third support point is located at the distal end of said rearwardly extending support member. 4. A cabled platform suspension system according to claim 3 wherein platform comprises a platform member and said rearwardly extending support member comprises a centrally disposed support strut affixed to a rear edge of said platform member and first and second tie elements extending between the distal end of said support strut and said rear edge of said platform member on opposite sides of said support strut. 5. A cabled platform suspension system according to claim 1 wherein said suspension points are respectively adapted to be secured to towers of a dry dock facility. 6. A cabled platform suspension system according to claim 1 wherein said platform comprises a V-shaped platform member having a central portion and first and second angled leg portions and including a support strut extending rearwardly of said central portion and having a distal end, said first and second support points being respectively located at distal ends of said leg portions and said third support point being located at the distal end of said support strut. 7. A cabled platform suspension system according to claim 6 wherein said platform further comprises a downwardly depending element affixed to the distal end of said support strut and first and second tie members connected between said element and said distal ends of said leg portions. 8. A cabled platform suspension system according to claim 1 wherein said platform includes a main platform and an elevator sub-platform movable, in use, between a ground location and a position on said main platform. 9. A cabled platform suspension system according to claim 1 wherein said platform includes a platform member, a centrally disposed, downwardly depending truss member and a plurality of tie elements connected between said truss member and distal ends of said platform member. 10. A cabled platform suspension system according to claim 1 wherein said platform comprises a platform member of a modular construction. 11. A cabled platform suspension system according to claim 10 wherein said platform member comprises a plurality of separate and removable platform sections. 12. A cabled platform suspension system according to claim 1 wherein said platform member includes a corrugated sub-deck. 13. A cabled platform suspension system according to claim 1 further comprising control means for controlling said cables to provide manipulation of the platform through a defined work volume, said control means including a tension sensor for each cable for sensing the cable tension in the associated cable. 14. A cabled platform suspension system according to claim 13 further comprising a pulley for each cable, each said tension sensor being disposed between a portion of said platform and the associated pulley. 15. A cabled platform suspension system according to claim 14 further comprising a winch for each cable, each said cable extending from the associated winch through the associated pulley to the corresponding support point on the platform. 16. A cabled platform suspension system according to claim 15 wherein said control means further comprises a motor including a rotating motor shaft for driving each of said winches and at least one of a position sensor, an encoder and a tachometer for monitoring a parameter associated with rotation of the motor shaft and means for controlling the associated winch in accordance with said parameter. 17. A cabled platform suspension system according to claim 1 further comprises securing means, including magnetic members, for securing the platform to at least one work site surface in order to stabilize platform positioning. 18. A cabled platform suspension system according to claim 17 wherein said magnetic members comprise a plurality of movable electromagnets. 19. A cabled platform suspension system according to claim 1 further comprising control means for controlling said cables so as to provide manipulation of said platform throughout a defined work space, said control means including a joystick controller comprising a base, a movable plate member simulating said platform and six linear potentiometers connected between said base and said movable member in manner replicating the connections between said six cables and said support points and said suspension points. 20. A cabled platform suspension system according to claim 19 wherein said control means further comprises a winch for each of said six cables, a power amplifier associated with each of said linear potentiometers and with each of said winches, for receiving a control signal from a corresponding one of said linear potentiometers and for, based on said control signal, producing a further control signal for controlling operation of the associated winch. 21. A cabled platform suspension system according to claim 20 wherein said platform includes a platform member and a rearwardly extending support tail, which is movable relative to the platform member to change the width profile of the platform and on which said third support point is located. 22. A cabled platform suspension system according to claim 21 wherein said platform member includes pivotable and extensible support arms affixed to the rear edge thereof, said support arms including distal push rollers for engaging a dry dock wall.