CCBC-455: Re-add cbcrc

This readds the configuration file feature for the cbc tools. This also
adds a new command called 'write-config' which can dump the current
configuration to its destination file.

Change-Id: I840316adf78daf8c84e7fd346bc4cc90053d8fc0
Reviewed-on: http://review.couchbase.org/38684
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>