Move gencode & genconfig back to ep-engine

Change-Id: Ia711001103a91d50b6601915f6498258e8c1d186
Reviewed-on: http://review.couchbase.org/33982
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>