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
generally if/for/while etc blocks should have a newline before and after... but variables closely relates can come right before (ie without newline)... like
bool unrelatedVariable = false;

bool isValid = ... ... && ...
while(isValid) {

}

bool hasCake...