Updated Makefiles to build on multiple platforms, cleaned up interfaces for csm2to3plugin and implemented several "stubbed out" methods in csm2to3model
Flushed out logic for csm2to3model::getVersion() and csm2to3Plugin::getModelVersion() and addressed code review comments, renaming csm2to3plugin::loadTsmPlugins() to csm2to3plugin::establishCsmPlugins()
Added comments for establishCsmPlugins