Added support for Node 0.11.13.

Updated to nan 1.20.
Corrected slight incompatabilities with libuv.

Change-Id: Iae131a203885554a2184717253e1ec368d36a93a
WIP: Updated to libcouchbase 2.4.0.

Change-Id: I08e50b59da9d6f546a4cedf699050cc6b447b88c