Settings: Add Advanced reboot option
By DvTonder

This commit adds a setting in Development settings for including options
in the power menu for rebooting into recovery or bootloader, defauled to
off.

When enabled, the Advanced reboot options will only be available once the
device is unlocked.

Change-Id: I692fb732ec1b14ae9a71f2de4b343a05934cdcf9
[1/2] settings: Set AdvancedReboot to be enabled by default
RE: http://jira.omnirom.org/browse/OMNI-1

Fixing as I am a stupid head

Edit 9001: Setting this to be enabled by default for all users

Change-Id: I08a0e0cbe821e4d2dad6cf2a9ac20721cd19d69b