Fix #65: Provide cmake config file

I've created a cmake config file that will be populated at build
time with the installed location of include folders and libraries.
I also restored the FindSimbody cmake module.
Update SimbodyConfig.cmake.in

Fix typo in SimbodyConfig.cmake.in
Fix SimbodyConfig.cmake.in

I was missing some of the cmake standard error handling
Set SIMBODY_VISUALIZER_INSTALL_DIR in root CMakeLists.txt

Otherwise the Simbody_ROOT_DIR is empty.
SimbodyConfig.cmake.in do find_libary for Simbody_LIBRARIES

Do find_library for each simbody library that we put in
Simbody_LIBRARIES, so that it can give the absolute path
that is known at build time.
Merge pull request #91 from scpeters/issue_65

Fix #65: Provide cmake config file
Update Exception.h

Change the bug reporting URI from simtk.org to github.com. Fixes issue #93.