major updates to panel

.make indentation and function formatting more consistent
.fixed headphone/speaker indicator
.truncate audio and change colour to red if muted
.show hdmi audio output
.add section for signal strength (only present if wireless connection)
.remove day from date (may add back?)
.show full brightness meter only just after it is changed (truncate to 1
of three characters otherwise)
.added pause icon if music paused
.made song info scroll when long
.made xtitle info scroll when long
.added gif showing some of this