IMS-VT: Peer capabilities

-Add support for peer capabilities

Change-Id: I3af365caaacb4c3c48f73a54da6e5de6bab321aa
IMS-VT: Change call data usage parameters

Change call data usage methods to take parameter of long type
instead of int

CRs-Fixed: 747694

Change-Id: I543aa082337d437ec7c2bf249bafb9658f34dd1b
Propagate the call substate changed message to the UI

Change-Id: I695736ccfa4e4446912ba6c3df1713bae6d4486a
CRs-Fixed: 749824
CSVT: Add CSVT service class for ImsManager.

Circuit Switched Video Telephony is supported with this class.

Change-Id: I9e3600543df5dc349244a9e7177a2a6b6ea08190
IMS: start and stop dtmf tones

Support of start and stop dtmf tones in Imsphone

Change-Id: I04f5d6f88088e5b77d314d4db9271fd49abf5dca
CRs-Fixed: 751797