We claim: 1. A modular manipulator comprising: a servo module having a plurality of winches, with corresponding servo axes and winch support structure, sensors, and drive mechanisms by which the winches are independently controlled, a support suspended from three attachment points and which can be positioned at various locations below said attachment points, said servo module mounted to said support, and at least six cables extending between said attachment points and said winches by which said support is suspended and positioned below the attachment points, said cables being wound up by and unwound from the winches to position the support at a selected location below said attachment points, wherein said servo module is one of a plurality of servo modules providing for reconfiguration of said servo axes and a variety of cable configurations, a combination of which provides the support with six degrees of freedom. 2. The modular manipulator as defined by claim 1, wherein said plurality of cables is any of six, seven, and nine cables. 3. The modular manipulator as defined by claim 1, wherein said support is a platform. 4. The modular manipulator as defined by claim 3, and further comprising a support spine extending from said platform, wherein said plurality of cables is nine cables, and wherein three of the nine cables are connected to said support spine to provide added platform constraint. 5. The modular manipulator as defined by claim 1, wherein said support is a spine and a spine bar, wherein said plurality of cables is seven cables, and wherein one cable pair from the seven cables is attached to the spine bar. 6. The modular manipulator as defined by claim 3, wherein said sensors include absolute position, velocity, and tension sensors, the tension sensors detecting cable tensions in respective cables. 7. The modular manipulator as defined by claim 6, wherein each tension sensor is disposed between said platform and a pulley about which one of said cables passes. 8. The modular manipulator as defined by claim 6, wherein each tension sensor is disposed between said winch support structure and a winch housing and senses cable tension approximately in-line with a respective one of said cables. 9. The modular manipulator as defined by claim 3, wherein said sensors include tension sensors which detect cable tensions in respective cables. 10. The modular manipulator as defined by claim 9, wherein each tension sensor is disposed between said platform and a pulley about which one of said cables passes. 11. The modular manipulator as defined by claim 9, wherein each tension sensor is disposed between said winch support structure and a winch housing and senses cable tension approximately in-line with a respective one of said cables. 12. The modular manipulator as defined by claim 6, and further comprising a controller by which the drive mechanisms are operated, wherein a set up and calibration operation is performed by: positioning said platform within a work volume with said cables unwound from said winches to initial cable lengths, setting said cable tensions so that they do not exceed a specified force while being unwound by an operator, connecting a first set of said cables to a first one of said attachment points, connecting a second set of said cables to a second one of said attachment points, connecting a third set of said cables to a third one of said attachment points, operating the winches so as to raise the platform up off a floor of said work volume, inputting platform angle and distance values into the controller, and determining a position of the platform within the work volume from said values. 13. The modular manipulator as defined by claim 9, wherein said specified force is no more than a five pound force. 14. The modular manipulator as defined by claim 1, wherein said drive mechanisms include, for each cable, a winch motor and a brake, and further comprising a computer which reads a desired load velocity and signals from said sensors, combines the desired load velocity with said signals, and computes commands for said winch motor and said brake. 15. The modular manipulator as defined by claim 14, wherein said commands are commands required to produce a desired winch velocity. 16. The modular manipulator as defined by claim 1, wherein said attachment points are disposed on any of walls, ceilings, support structures, cranes, bridges, and radio towers. 17. The modular manipulator as defined by claim 4, wherein a tool is attached to an end of said support spine so as to be maneuverable into close tolerance areas. 18. The modular manipulator as defined by claim 5, wherein a tool is attached to an end of said support spine so as to be maneuverable into close tolerance areas. 19. The modular manipulator as defined by claim 6, and further comprising an operator interface permitting entry of operator override commands. 20. The modular manipulator as defined by claim 1, and further comprising an operator interface permitting entry of operator override commands.