Add week 2 reports

(At least, the ones that I have)
Merge branch 'master' of github:szmoore/MCTX3420

I keep forgetting; `git pull` before `git commit` avoids these crappy merge things.
Delete helloworld.c

Why is this still here?
Changed directory structure, updated READMEs

Create directory "rpi" for anything that runs on the Raspberry Pi.
Merge branch 'master' of https://github.com/szmoore/MCTX3420.git