Make ice_active property dynamic

Ignore-this: 3653f9f448894a2a8f03dfaf7ab809ee

darcs-hash:20140516100538-56b4d-c9162198d802262c23e76ec31c783fca7003d7ae
Fix use of SIP method in notification data

Ignore-this: 412a5be6aa92e8108415b08b3be4e26b

darcs-hash:20140516103210-56b4d-f41b085a4dedd11cf7bbd1362d92038ce5f3f03c
Make sure session state and proposed_streams are set to correct values when processing proposals

Ignore-this: d6ec40c25d328813febe1c475ba0b916

darcs-hash:20140516103847-56b4d-734f550c54fd1a48988510c3e7f8e0a5ecb72254