Merge pull request #2 from guangmingyao/black_dev

Black dev
change colors and some minor changes
correct date
Merge pull request #3 from KellyBlack/black_dev

Black dev
date
clikcer number
Merge pull request #4 from KellyBlack/black_dev

Black dev
clicker quiz 3
Merge remote-tracking branch 'origin/black_dev' into yao_dev
Merge pull request #5 from KellyBlack/black_dev

Black dev
clicker quiz sec 3
week3-day2
Merge remote-tracking branch 'origin/black_dev' into yao_dev
week4 day 2, example cube root of 3
week4 day 2, add = and i to last two pages
Merge pull request #4 from guangmingyao/yao_dev

Yao dev
Merge pull request #6 from KellyBlack/black_dev

Updates for wed, sep 19
no change
no change
Merge remote-tracking branch 'origin/black_dev' into yao_dev

Conflicts:
	notes/DifferentialEquations.tex
	notes/week4-Day3.tex
Added images for plotting complex numbers.