ENH: remove reliance on OpenFOAM etc/config.sh/functions file.

- similar functionality in etc/tools/ThirdPartyFunctions to improve
  the independence of ThirdParty while reducing clutter in the callers.

- add useGcc function for convenience
- mask seeing our own git-repo when building

STYLE: various items

- eliminate old user-editable configuration in files - now command-line only.
- use *_BUILD_DIR instead of *_BINARY_DIR for more clarity of the purpose
- drop use of '-q' option for wmakeCheckPwd (already has stderr redirect)
- drop checkVersion for makeParaView since it stopped working properly
  with newer paraview version

CONFIG: update list of versions