For displays where the primary mode is 2160p, check to see
if a 1080p mode exists, and if so, use it. This allows laptops
with native 4K panels to specify a 1080p video mode via kernel
command line and have fbwhiptail use that vs native resolution.

Test: boot Librem 15v4 with kernel param 'video=eDP-1:1920x1080'
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

Only GTK mode works with a moving target (by pressing any key), and
the console mode will just show the initial percentage and exit when
Enter key is pressed. Handling of stdin values is still to be added.

This will automatically try to use the Linux FB driver if it can't
find a suitable DRI device or screen. If it can't create a FB with
double buffering, it will use a single buffer instead.
This will print the escape char to hide the blinking cursor and restore
it at the end, since it would affect the framebuffer. I don't know how
it will react if the terminal doesn't support the escape sequence.

To test on a DRI-enabled machine, simply comment out the line :
//dri = cairo_dri_open("/dev/dri/card0");

Error prints from the linux fb driver still need to be removed, they
are left here for now until further tests are done.

Removing the two useless test pngs from initial commit and replace
the code in the test apps to glob for app icons in /usr/share/icons
and load the png files from there instead.

This will get the smallest resolution between the multiple screens
(taking the preferred (max) mode for each) and will then draw the menu
on this smallest size image, then display it centered on the screens.

Remove the reflection on buttons.
Make the default background into a black->grey gradient.
Remove --background-gradient from whiptail wrapper script.
Make the frame have a diagonal gradient instead of on a top-bottom path.
invert colors from the frame gradient with regard to the background.
Make the title grey.
Change the selected button color from blue to light grey.
Increase the dropshadow to 8 pixels.

Also print usage and version now.