Fix dptr corruption in EPn interrupt handlers.

Compute bitstream ID and avoid rebuilding bitstreams if it matches.

Add `glasgow build` command to build applet bitstreams offline.

Update MPNs for out of stock capacitors and resistors. Also fix a few MPNs that didn't quite match the manufacturer format, and assign a MPN to J4.

Use Mfg/MPN fields in schematic instead of Mouser_PN. There's no point in having Mouser_PN; pretty much every service, including Mouser itself (!), works better (or even at all) with MPNs.

Fix accidentally used 0201 resistor.

Allow flashing bitstream to ICE_MEM. This also removes `glasgow test download` command in favor of `glasgow run --bitstream`, allows using CLI arguments in applets when building gateware, adds logging, and improves robustness of EEPROM handling code overall. Fixes #55.

Add EP type to USB endpoint string descriptions.

Update libfx2 to use EEPROM page writes. This also forces 400 kHz I2C mode to be used, and adds verification for `glasgow flash`.

Flush GlasgowPort when it is garbage-collected. Too easy to never call flush() explicitly and end up wondering why nothing happens...