add RSPEC_VERBOSE and RSPEC_OPTIONS

with verbose mode turned on, the list of the rspec files are printed up front.

A bunch of blog posts suggest turning this off to pare down the nightly "build" logs.
It would be nice if `RSPEC_VERBOSE=false` for builds.

Also, added `RSPEC_OPTIONS` to let people run their own.
It would be nice if cruise control had `RSPEC_OPTIONS=.rspec_cc` instead of using `CC_BUILD_ARTIFACTS`