Check for dfu-util and screen before using them. Also aborts if
teensy_loader_cli compilation fails.

Uses the type builtin to determine if a command exists. See here:
https://gist.github.com/sdelmas/7377271

Convert README to Markdown format.

This makes it render nicely on GitHub's website, as well as having a
consistent plain-text format that should be familiar to many.

- Fastload option (allows for remote flashing)
- Autoscreen option initiates screen after successfully loading the firmware

- Currently actual detection commented out due to issues

cmake -DREFRESH_KLL=1 ..

- Added AddModule CMake function which simplifies specifying module requirements

- When loading a garbage image onto the device, the chip hangs
  and refuses to jump to the bootloader and start dfu

Fix
- Check if chip was in locked state and jump to dfu
- Check if watchdog timer fired and jump to dfu

- Currently builds larger binaries than gcc (RAM)

- Not ready yet
- Will require some more changes to Lib/mk20dx.c

Fix an off by one error causing most keys to be shifted one to the
right, due to the missing backslash (\) key in the top row.

Fix an off by one error causing most keys to be shifted one to the
right, due to the missing backslash (\) key in the top row.

Latch now activates on key release, and deactivates on next key release.

- Had to re-write descriptor to support Windows 8.1 while still working with Mac OSX
- NKRO keyboard is now more bandwidth intensive as all the keys must be updated at the same time
  (due to 8.1 bug in the HID spec)

- Modifier byte was being cleared after each send (needed for Boot Mode only)

- Fixed descriptor to not include USB Code 156 (Clear)
- This USB Code affects repeating Delete

- Minimum protection size is 4k on the mk20dx128vlf5

- OSX doesn't properly follow the spec when it comes to padding bits (when using bitfields)
- Everything seems to work when I don't use them
- NKRO tested working on OSX

- Also updating usbMuxUart header with most recent keyboard defines

- Tested both with Boot and NKRO modes

- Was causing lock-ups until the serial port was read
- Also checking each of the NKRO key types in each send loop

- It's possible to get even more, but this is probably as far as I'll go
- PROGMEM is really annoying to use, and makes the code look like ass
- Now the Teensy 2++ should have enough RAM to use PartialMap easily

- Use CMake -D arguments to set variables (so you don't have to edit the CMakeLists.txt file)

- Missing a byte in the array

- Thanks hasu for pointing it out
- Keycode 50 is problematic under Linux, so removing (it's a duplicate keycode anyways)

- 128 bytes is invalid for USB 2.0 Full-Speed (max 64 bytes)

- When changing the mode, a key buffer flush is required (might confuse the OS temporarily)