Add an option to change the device hostname (2/2).

This adds an option to modify the device hostname used
in ip resolution. This is useful when connecting to the
android device in a dynamic dhcp environment.

Change-Id: Ibc145b74036617248d4f33c6866cc9c8a8cc8974
Settings: Fix wifi developer options summaries

Change-Id: I85688d59685d3a0b0a48e51581eee77ebc7cd2fa
Developer Options: launch the Development app

Change-Id: I0f798d197888ef7f40688009536040e061c410f4
Settings: Hide Development settings when it is turned off

This commit hides the Development and Performance settings items
when the user turns off Development settings. This sets things back
to tapping x number of times on the build number to once again enable
developer settings

Change-Id: I6003f73f5abee54bb000f01757ecffe7b68dba59
Development Settings: fix setting reset on disable

When Development Settings are disabled, some settings are
reset to values other than the default. This fixes it.

 - Adb notify should reset to enabled

 - Verify apps over usb should reset to enabled

Change-Id: Ifa1ee25cfab32b7a236e02055006f0d2a4b07f37
Fix NPE.

When entering the notification prefs sub activity without the increasing
ring pref being visible and leaving it right away, onActivityStop()
threw an NPE because the handler wasn't yet constructed.

Change-Id: Ia4291d8ac3d1dbf76d432db7e0e973844163c4ae