BUILDEM_ENV_STRING: Add CC and CXX environment variables, based on CMAKE compiler vars.
Merge branch 'master' of ssh://github.com/stuarteberg/buildem
Merge branch 'master' of https://github.com/janelia-flyem/buildem
vtk.cmake: Added explicit search path to linker flags.
opengm: Added a patch to let us skip the sphinx docs build with a cmake switch.