Recording email subject

This is the subject of the email that is sent to a user when a new recording is available. Available variables are:

• <TMPL_VAR NAME=TALKTIME_DISPLAY> is the duration of the recording in human-readable format
• <TMPL_VAR NAME=CALLERID_WITHHELD> Boolean, takes the value of 1 if the caller ID is withheld
• <TMPL_VAR NAME=XXX> Name of any column xxx from table 'recordings', referring to the recording that was created