rtcds cli: add 'version' command, and overhaul some command parsing and help

change 'log' to 'blog', for 'build log', in case we add a separate command
to view the actual run-time log of a model.

git-svn-id: https://redoubt.ligo-wa.caltech.edu/svn/advLigoRTS/trunk@4521 6dcd42c9-f523-4c6d-aada-af552506706e