Check in a reference firmware image

The firmware is feature-complete now, and this will save folks the trouble of downloading a huge toolchain. Plus I like to keep tabs on the quality of the assembly output :)

README.md

@@ -65,8 +65,8 @@ For more information, see the [Server README](https://github.com/scanlime/fadeca
 Prerequisites
 -------------
 
-* The recommended ARM toolchain, from <https://code.launchpad.net/gcc-arm-embedded>
-* The Teensy Loader: <http://www.pjrc.com/teensy/loader.html>
+* To install a firmware image, you'l need the Teensy Loader: <http://www.pjrc.com/teensy/loader.html>
+* To recompile the firmware, please use the recommended ARM toolchain from <https://code.launchpad.net/gcc-arm-embedded>
 
 Pin Assignment
 --------------