Settings: use SwitchPreference instead of CheckBoxPreference

be consistent....lp is using now SwitchPreferences

Change-Id: I794b699e9bc7819efc02886064121e0992c7214a
Settings: add safe headset volume and less annoying sound notification

Add settings for both features.

Screw'd, slightly chopped

Change-Id: I8ab4f4b9ec320238b05ac51fb76ac24b93c37d37
Option to use volume keys to control media volume anytime [2/2]

The volume keys control the Media volume rather than the Ringer
hence removing the issue of accidentaly changing the Ringer volume.

Screw'd, slightly chopped

Credits: Pawitp

Change-Id: Ic0a1c04ae41eac65e9535d6de5f11c0456730315
Add an option/category in Dev Set to customize the device hostname (2/2).

PS2:
- cleanup

Change-Id: Iee14e90fa6fb6a13a123d92b7cf6dceaf6d18ffc