native uxn emulator for plan9front

state:
  * implemented fully:
    - uxn core
    - system device
    - screen device
    - datetime device
    - controller device
    - console device
    - mouse device
  * implemented partially:
    - file device
  * not implemented
    - audio device

INSTALLATION

  ; mk
  ; mk install

  if you wish to use uxncli, duplicate `uxn9' to a `uxncli' file.
  it can act as it.

USAGE

  uxn9 [-S] [-f targetfps] file.rom

  -f number  changes the target fps
  -S         turns on smart drawing debug mode on