freeswitch: rework init & hotplug

freeswitch: rework init & hotplug

This adds a term_timeout uci option which can be used to change the
default timeout that procd uses while waiting for freeswitch to exit
once the TERM signal is sent. freeswitch may take a bit longer to exit,
so adding this option is likely appreciated. By default procd's default
is used, though.

Logging is updated in init script and hotplug script. The used facility
is changed from user to daemon, for instance.

An issue was fixed in the parsing of the ntpq output. In case a positive
offset was printed the parsing failed. Apparently ntpq is now adding a
'+', so this is now accounted for.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>