create cyclus.h. added missing header install
down-selected includes in cyclus.h.  Removed remaining vestiges of converter models
added cli flag for printing cyclus include dir
fixes build error for macs, moves mac linker flag to top of cmake file to set the flag for all compiled libraries in the build
removed verbose linking flag
Merge pull request #605 from rwcarlsen/cyc-header

create cyclus.h. added missing header install. fixes #572.
fixes mac build issue where special mac linker flag wasn't being set due to PARENT_SCOPE error in cmake file