Renamed scanner squelch to trigger
Added squelch for audio output

DEBUG -> PERIPHERALS is now a buttons based menu

Change icon colours in debug menu

Fix disappearing icons

Icons disappear when they are rolled over using the jog wheel and the colour is set to
ui::color::white()
Fixed by changing the colours of the icons to something other than ui::color::white()

UI menu changes (#41)

* UI menu changes

Changed DEBUG menu style from text / scrollbar into buttons.

* Update ui_debug.cpp

Upstream merge