Multiple copies of libcouchbase release notes abound

We shouldn't have multiple copies of the libcouchbase release notes. We should have only one master set of the release notes.

Copies exist in these places:

• C SDK guide: http://docs.couchbase.com/developer/c-2.4/release-notes.html

• C API reference here: http://docs.couchbase.com/sdk-api/couchbase-c-client-2.4.7/md__r_e_l_e_a_s_e__n_o_t_e_s.html.

• And in every other version of the C API reference (just change the patch version in the URL given above for the API reference you get a list of the release notes through that version.