###struct
- Sipdroid (Main launcher)-> send dial action (android.intent.action.CALL)
- SIPUri (dial action intent receive activity) -> Receiver.java(engine method return SipdroidEngine.java)
- SipdroidEngine (startEngine(method listen) and method call(target,true)) -> UserAgent.java( method listen and call)->
- ExtendedCall.java(method listen and method call) -> ExtendedInviteDialog.java extends InviteDialog(method listen and method invite)-> Dialog.java(method changeStatus) -> Sipprovider.java(addsipproviderListener)
- transaction/InviteTransactionServer.java(method listen)