Install python c modules with . in the filename (Windows/Linux)
When moving to python 3 we found that Python modules are given names like libtomvizExtensions.cpython_36m_darwin.so. The python module installation code was stripping the whole extension and failing to find libtomvizExtensions. I have modified the OSX install code to only strip the trailing .so/.py here !235 (merged), but I don't have time right now to check the other platforms to see if they also have this problem and need similar fixes.