deprecate getManifestEntry
deprecate getManifestEntry

Summary:
Indicate getManifestEntry is deprecated so we remember to delete it
down the line.

Reviewed By: genevievehelsel

Differential Revision: D19459793

fbshipit-source-id: 86dd173cfb12c36cf6ba19eaf4be96dfe624c05f

facebook/watchman,nodakai/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman