Quiz1: hmac_strcmp
Rename c dir to quiz.

git mv c quiz
git commit -a
git push origin master:master
Added exported files from mbed
Added HW3
UCSC e4357 Extension: Homework Updated
Added Quizes
Added Q0
Merge remote-tracking branch 'upstream/master'

This is my first time to attempt to merge an upstream/master with my own master.
Adding source files for digital I/O exercises for 14.1 and 14.3  -Drew (Tues Oct 28, 2014)