OSD channellist - new version

OSD channellist including three windows - channellist, now and next and event info windows.

Keys:
c - display channellist / change to selected channel
d - down (channellist and now and next) 
u - up (channellist and now and next)
r - right (change focus channellist <-> now and next windows)
l - left (change focus channellist <-> now and next windows)
n - next 12 channels in list
p - prev 12 channels in list
e - exit 
m - menu (quick and ugly thing to display the bitrate)

Some HDMI-CEC keys are also added.

Other info:
graphics_resource_text_dimensions_ext is kind of slow so font widths are cached to enable faster OSD display.
The input thread floods the msg queue so added a hack to prevent to fast key repeats.
 
BR

//Daniel