Update meta for release 2.1.0

Package version will be 2.1.0
Library version will be 2.0.8, because it is still backward-compatible
with all 2.x versions

Change-Id: I495e1037332fada0efdb9a3b88bb72a17c796059
Reviewed-on: http://review.couchbase.org/28332
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Matt Ingenthron <matt@couchbase.com>