Add couch_debug:opened_files_contains/1
Add couch_debug:opened_files_contains/1

couch_debug:opened_files_contains is an efficient way to find out list
of file descriptors or couch_file processes which path contains given
substring.

fkaempfer/couchdb,apache/couchdb-couch,fkaempfer/couchdb,apache/couchdb-couch,fkaempfer/couchdb,apache/couchdb-couch,cloudant/couchdb-couch,cloudant/couchdb-couch,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,cloudant/couchdb-couch