Tune all display devices to have 64MB VRAM. Close #211

64MB VRAM is sufficient to run 3840 x 2160 with page flipping., even though qemu support a max of 2560x1600. No need to tune this since 64MB is relatively small in the great scheme of things.

References:
  - https://www.ovirt.org/develop/internal/video-ram.html
  - https://stafwag.github.io/blog/blog/2018/04/22/high-screen-resolution-on-a-kvm-virtual-machine-with-qxl/
  -

quickemu

@@ -693,8 +693,9 @@ function vm_boot() {
 
   # Allocate VRAM to VGA devices
   case ${DISPLAY_DEVICE} in
-    bochs-display) VIDEO="${VIDEO},vgamem=134217728";;
+    bochs-display) VIDEO="${VIDEO},vgamem=67108864";;
-    ati-vga,cirrus,cirrus-vga,qxl,qxl-vga,VGA) VIDEO="${VIDEO},vgamem_mb=128";;
+    qxl,qxl-vga) VIDEO="${VIDEO},ram_size=65536,vram_size=65536,vgamem_mb=64";;
+    ati-vga,cirrus-vga,VGA) VIDEO="${VIDEO},vgamem_mb=64";;
   esac
 
   # Add fullscreen options