Fixed issue with MutateInSpec value encoding.
Fixed issue with MutateInSpec value encoding.

Change-Id: I5e08be591aaa6d9e663ec73f5fe1062e64385e7c
Reviewed-on: http://review.couchbase.org/115724
Reviewed-by: Charles Dixon <e13bf4498b4994e133fd3586350658dc4a59329a@gmail.com>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

couchbase/couchnode,couchbase/couchnode,brett19/couchnode,couchbase/couchnode,brett19/couchnode,brett19/couchnode,couchbase/couchnode