POT, generated from r8103

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8104 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Cache the friendship request user IDs for a given user.

This commit:
- Caches calls to BP_Friends_Friendship::get_friendship_request_user_ids()
- Invalidates the friend request cache when a friendship is saved or removed
- Adds unit tests

See #5435, #5414

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8105 cdf35c40-ae34-48e0-9cc9-0c9da1808c22