add --enable-timerfd-wrapper to wrap timefd syscalls for platforms with the right kernel and wrong libc

Libpri doesn't do that for us, so handle things on our end.
Other parts of the previous patch seem to work fine.
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

add execute_on_fax_success, execute_on_fax_failure and execute_on_fax_result channel variables to trigger an app or lua script when a fax result is received

auto populate global origination_caller_id_name/number from effective_caller_id_name/number in enterprise originate

Adds a new "overlapdial" configuration parameter that enables
incoming overlap dialing when set to "incoming", "yes" or "both" (possible values:
"no", "yes"/"both", "incoming"/"receive", "outgoing"/"send").

(Overlap dialing is disabled by default)

NOTE: only the non-overlap receive case has been tested (= doesn't break existing setups)
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

See FS-3379

ftmod_sangoma_isdn.c:ftdm_sangoma_isdn_io_run()
	remove unused variable wflags.
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

ftdm_io.c:ftdm_channel_process_media()
	status variable was set but otherwise unused
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>

add sip_liberal_dtmf chanvar and liberal-dtmf profile param to use the maximum methods of DTMF avoiding sticking to the spec which leads to incompatability

FS-3367 --resolve the start was actually broken in the same way, instead of your exact patch I replaced both original functions to work as your patch suggests