Dialer invocation from SMS bug 838000 r=borjasalguero

changes to implement invoking dialer on tap of phone number in phone, and invoking contact menu with ability to dial, create new contact and add contacts whenever a phone number is long pressed.

Change 1: Use action_menu.js to dynamically construct the menu for long press
Change 2: use webactivity to invoke dialer, contacts from sms
Change 3: created method to detect phone number in the message and attach event handler to invoke action_menu on long press and dialer on tap.
Change 4: added unit test to detect different phone number formats.