Merge pull request #6 from mikem5/master

Getting solutions.pdf to compile correctly
Merge pull request #7 from mikem5/master

7.11 full, 7.12 partial
Added 7.3.
Update 06.21.tex
Merge pull request #8 from alexbeams/master

Update 06.21.tex
 Added 7.2 and 7.7
7.16
Merge remote-tracking branch 'upstream/master'
07.13, 07.16, cleanup