permissions: improve behaviours

This patch handles more efficiently the new Android permissions system.
Here is the new behaviour :
    - at first launch, we ask for the main necessary permissions :
        ie: Microphone, Contacts and Camera
    - if the user refuses Microphone, the app can not run properly, so
        it is automatically closed
    - if the user refuses any of the two other permissions, the app
        does not propose them anymore. The user has to trigger them
        from his Android applications settings, or thanks to the app
        in the settings and edit account screens.
        In this last scenario, we propose this previously denied per-
        mission.
    - if the user denies a permission with the "Do not ask me anymore"
        option enabled, he will have to activate them from the Android
        applications settings.
    - when the user creates his account, the Video Enabled settings is
        initialized with the value of permission grant.

Tuleap: #545
Change-Id: Id7e6a5955a621c018886335c6626fe5c6ca85d1c