Is your feature request related to a problem? Please describe.
Currently, oxide has to save the screen for every application after freezing them, and then recall it before resuming. This adds some latency, as well as odd timing issues like #105

Describe the solution you'd like
Every application should have their own framebuffer, and tarnish should handle determining which frame buffer should be drawn to the screen. This would also allow for notification display to be handled better as you can ignore portions of the application framebuffer and composite in the notification area.

Additional context
ddvk/remarkable2-framebuffer#4 (comment)