Address Sherm's comments about cmake macro.
Clean up OPENSIM_ADD_LIBRARY macro.
Merge pull request #221 from opensim-org/cmake-library-macro-2

Cmake library macro 2
Start cleaning up exp-based reporter plugin cmake.
Convert examples to use OpenSimConfig.cmake.
Remove unnecessary line from wrapping cmake.

Also, clean up an api example CMakeLists.txt.
Application tests need not specify simtk libs.
Have lepton use OPENSIM_ADD_LIBRARY macro.
Convert simmFileWriter to use OPENSIM_ADD_LIBRARY.
Do not copy simbody files if not windows.
OpenSimConfig provides Simbody paths.
Fix merge conflicts.
Significant progress.

TODO: etc/buildinfo.txt
TODO: sdk/doc/BuildOpenSimPluginSteps.pdf
TODO: Vendors