Re-Add V3 API

This adds the version 3 API with more documentation and details. The API
is also converted to contain names more consistent with the newer style
of lcb_TYPE rather than lcb_type_t

Change-Id: I6fc509f09bc4aeffcc4c2f64c63dc6786c20ac6c
Reviewed-on: http://review.couchbase.org/36428
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>