Rename lcbio_EASYPROCS to lcbio_CTXPROCS

The older lcbio stuff called this "EASY" because there were two
variants. Now that there's only one, the old name no longer makes sense.

Change-Id: I3f0275c4ba137921cad2719faebc1d09c69f8e60
Reviewed-on: http://review.couchbase.org/42448
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>