CMake/Check-All: Allow for specifying runtime linker paths for tests

Change-Id: Icd2f17de3eb9220d4e27972035db2a6c27e78090
Reviewed-on: http://review.couchbase.org/33852
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>