call-forwarding: Update conditional reporting logic

Don't report conditional cfs when cfu is active
call-forwarding: Emit signals when cfu is toggled

Emit signals to mask/unmask conditional cfs on cfu
activation/deactivation.
call-forwarding: Minor code refactoring
call-forwarding: Fix various style issues
hso: Don't access freed data, in hso_set_online
atutil: Ignore invalid CLCC results

Some phones report CLCC calls with out-of-range info.  E.g. call index
being 0 (it is 1 based according to 27.007) and call states being
reported as '6' (valid call states are 0-5.)
sms: Disable sending AT+CNMA with SIMCOM quirk

SIMCOM SIM900 modem module not support AT+CNMA command
sim900: Use SIMCOM quirk for SMS atom
Release 1.5
voicecall: Fix strange GTA04 modem CLCC behavior
emulator: fix notify_ring

notify_ring should not use information from waiting call
voicecall: Don't set indicators during transitions
sim900: Add ussd and voice call support
voicecall: Improve transitions check

Indicators should not be updated if:
- multiple separate calls are active at same time
- a conf call and a call are active at same time
- multiple separate calls are held at same time
- a conf call and a call are held at same time
- a conf call has call in active and held state
call-forwarding: Remove cf_list_clear()

Use g_slist_free_full() instead.
call-forwarding: Inline get_query_next_cf_cond()
gisi: Remove includes of <glib/gtypes.h>
isimodem: Remove includes of <glib/gtypes.h>
emulator: Force indicator event implementation
voicecall: Force callheld update after calls swap

In HFP spec, a callheld indicator update should be sent after swapping
calls, even if it stays to 1 (AG has both active and held calls).