Call management

[KPalvolg]

Added incoming call notification loop:

• Triggered by "type": "incomingCall" in notification data
• Displays name from "name" member in notification data
• Reports call as video call if "isVideo" is true in notification data
• Notification repeats every 3 seconds for a total of 24 seconds
• Plays Ringtone.caf file with the notifications
• To wake app, notification sounds should be _blank.caf, "priority" should be "high" and "content_available" should be true
• Only one call notification is allowed at a time, others will be ignored
• Call can be stopped from code, or by waiting for it to time out, or by receiving a stop call notification

Added stop call notification handling:

• Triggered by "type": "stopIncomingCall" in notification data
• Stops current notification loop and will show a missed call notification
• Displays name from "name" member in notification data
• Reports call as video call if "isVideo" is true in notification data

Added JS methods to:

• Report incoming call
• Stop call
• Stop call and report a missed call

[KPalvolg]

Not used, due to limitations with APNS