Fixes & missing stuffs
Ability to disable hardware keys via nav bar settings (1/2)

cm_strings.xml already committed

<string name="hw_keys_title">Hardware Keys</string>
<string name="key_menu_enabled">Menu Key Enabled</string>
<string name="key_back_enabled">Back Key Enabled</string>
<string name="key_home_enabled">Home Key Enabled</string>