If max tries is reach and user has not made a valid entry then system transfers the call leg to the specified destination.

This prevented 'make mod_callcenter' from working because the 'all' in
'callcenter' was matching.

FS-3510 --resolve make all instances of execute_on_X uniform with api_on_X and support both prefix vars as before and usage of arrays to push several exexute_on or api_on records into one variable

FS-3503 --resolve mod_callcenter: add DNIS in some event, and add a few API like get uuid and get state for agent

FS-3505 --resolve copied same code from the other place the original intention was to behave as described in the bug report but it seemed like a reasonable enough request

back off locking contention so you can query for other interfaces while a module is loading that locks the interfaces hash

erase files before recording in VM to make append impossible and write to tmp copy when recording greetings/name so it's not installed until finalized