Squashed commits
Updated tutorial for HW4 on Macros, based on feedback
gnumake
Merge pull request #631 from atost001/cs100-2014fall

HW4 Boost - Containers and Tribools
Merge pull request #638 from nickzoo/cs100-2014fall

gnumake
Merge pull request #633 from khuan013/cs100-2014fall

Updated tutorial for HW4 on Macros, based on feedback
added syscallvideos.md for hw4

added link to video guide in hw0

added link to video guides in hw1

added link to video guides in hw2