Fix improper operator key acceptance and clean up temp recording files.

Fix improper operator key acceptance and clean up temp recording files.

This is a fix for when pressing the operator key after recording an unavailable,
busy, name, or temporary message in mailbox options. The operator key should not
be accepted here, but should be allowed during the message recording. If the
operator key is pressed during ensure the file is saved or deleted as
apporopriate.  Also, ensure removal of temporary recorded files after an early
hang up or when message acceptance confirmation times out.

ABE-2518

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@292223 65c4cc65-6c06-0410-ace0-fbb531ad65f3