add support for configuring couchbase XDCR (replication) and bump to v3.0

needs testing but submitted for early review
ouch you're right -- the character *before* the version is `-` for `3.0.0-centos`, and `_` for everything else (other `3.0.0` OS's, and all OS's in 2.x).  whereas the character *after* the version is always `-`.  i had the check in the wrong place.

i suggest another driver method for that character rather than complex freemarker.