Foboot 4MB Wraparound Fixes

This release fixes an issue where loading a large file (> 4 MB) would cause the image to wrap around and overwrite the bootloader.

v2.0.3: Fix USB Reset IRQ

This release fixes the USB Reset IRQ so that it doesn't constantly fire during a reset. Rather, it fires once at the start of the reset.

This should increase stability on a variety of machines, particularly when using tinyusb. Under those circumstances, resets could be as long as 100 mS, during which the CPU was functionally unusable.

This release is compatible with the circuitpython release.

v2.0.2: sw: don't clear OUT buffer during usb_recv

If there is data already in the OUT buffer, don't throw it away.

This was necessary when using `epfifo` due to the way it shared OUT and
SETUP packets.  However, it is causing reliability issues with eptri.

Signed-off-by: Sean Cross <sean@xobs.io>