New Functionality 
1. Added GUI to use more than 2 external forces in various tools (used
to be up to 2).
2. Speedup of IK tool.
3. New "Debug" mode for troubleshooting.

Documentation:
1. Fully updated Users' Guide and Developers' Guide

Bug Fixes:
1. Bug 1026: Marker editor throws exception on renaming markers.

2. Bug 1022: ViaPoints from earlier versions of OpenSim not imported
correctly.

3. Bug 1013: Incorrect muscle paths with wrapping in 2.0

Notes:
1. Platform dependent libraries are included, depending on user's 
development environment, the corresponding binary distribution is 
required. This is relevent only to API users. GUI users can use any
distribution..