W3C Telephony API implementation.

Implements the latest W3C Telephony API specification found at http://telephony.sysapps.org/
Requires the oFono telephony middleware and the BlueZ Bluetooth middleware for working with paired phones.

BUG=XWALK-1419
These are just auxiliary structures. It's shorter, more readable and more concise to refer to them as structure fields. 
The naming I can change, although it would be more consistent to use these names, since they also figure under the same name in the spec. If someone who reads the spec, then reads this code, it would be much easier to understand.

But to have accessors would blow up the code by a lot of unnecessary lines and without any benefits, and it would be much less readable.