Confmon: Use lcbvb_save_json() and lcbvb_replace_host()

This new function will serialize a configuration file to JSON. Thus it
is no longer needed to carry the original configuration string around.
The lcb_clconfig_create() function has been modified to accept only two
arguments, eliminating the weirdness surrounding the middle 'raw'
parameter. Additionally bc_file will now use this method to generate the
string.

Change-Id: I7dc2069f779c27b3934120586e36ff831e5c4d2e
Reviewed-on: http://review.couchbase.org/37563
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Brett Lawson <brett19@gmail.com>