mchck.mk: gdb + flash targets only for mchck
mchck.mk: give host a lib as well
vusb: enqueue new urbs on tail
vusb: complete SETUP transactions in one go
usb: pass ep pipe handle to usb_rx/usb_tx
toolchain: more host lib
usb: add usb_init_ep
dfu: add USB_DFU_TRANSFER_SIZE
lib/mchck: drop builtins.h, move to system.h
usb: add identity reset handler
add TODO
mchck.mk: generate map file on link
usb: mega descriptor change, wip
TODO: verify resonator stability
gitignore: update
clean up submodules

- the wiki submodule has been too much effort to update without gain
- pirate-swd-nuc1xx has been replaced by our programmer
schematic: mark components as optional, rearrange power routing
r5 layout
hardware/Makefile: adapt to kicad file name changes
move user-accesible capacitor outside