view: use a notebook for dialpad

Also, removed the alignment widget since it is deprecated.
controller: trivial code style fix

Remove the space for the i18n call.
Add IncomingCall widget

It's a dialog for accepting or rejecting a call.
sounds: verify that the current id is not zero

This is a very strange situation. The real fix should be somewhere else.
call-incoming signal has three parameters
controller: nullify call_token at hangup
view: clean location entry at hide controls
view: use property rather than method
on call incoming the ui state is ringing

Not alerting.
gopalpcssep: extract the correct token
model: add {accept,reject}_incoming_call()
view: handle IncomingCall widget
controller: control the incoming calls
view: normalize the ui state operations
add a shell script to show the history table
soundgst: don't close at Close()

We are sharing a unique gstreamer backend, we shan't close it.
mmbackend: log when closing
handle gracefully when local busy