add hint about what the recovery password field is for
always emit the preSetPassword hook, this should only indicate the intention. Finally the post-hooks indicate if it was successful or not
use pre_setPassword hook to update the encryption keys if the back-end doesn't support password change; improved output to let the admin know what happened
Merge pull request #3610 from owncloud/encryption_recovery_for_ldap

recover encryption keys if ownCloud can't change the log-in password