Merge cbbackup and cbbackup wrapper

The existence of both cbbackup and cbbackup wrapper is confusing for users. cbbackup is too slow on its own and for any real world sized bucket the wrapper must be used. There isn't any mention of this in the documentation and there isn't any documenation on the wrapper @ http://docs.couchbase.com/admin/admin/CLI/cbbackup_tool.html

The parallel functionality of the wrapper needs to be included into cbbackup and the wrapper deprecated. Additionally the parallel function needs to be smarter. Currently the wrapper is defaulting to serially backup 100 vBuckets per child cbbackup process, this should be smarter and default depending on the number of vBuckets per node and the number of CPU cores. For instance in a 15 node cluster there's 68 vBuckets per node, defaulting to do 100 vBuckets serially means that there's actually no parallel backup happening.