Sync with upstream

[tbsp]

This PR merges uxn upstream changes, and updates the uxnvita uxnemu to work with them. I've tested a handful of the primary roms, which seem to function as expected (launcher, calc, piano, noodle).

The main changes from upstream are:

• File device now supports two files
• Audio calls changed to take instance integer instead of UxnAudio pointer
• Addition of Screen/auto byte

[ivodopiviz]

Thanks a lot for this! I’ve been unable to work on uxnvita for quite a while.