Typo -- "every characters" -> "every character"
Integrate suggestions from issue #59
Integrate suggestions from issue #60
Clarify section on == and null/undefined
Integrate edits for chapter 8
Another pass over chapter 11
Update generated SVG files
Another pass over chapter 12
Another pass over chapter 13
Integrate edits for chapter 9
Update cover
Fix typo in chapter 3
Integrate copyediting for chapter 1
Put operators in regular code font
Fix repeated word in chapter 4
Add missing word to chapter 4
Include font files

For offline work and quick loading.
Switch to rgb rather than hash colors, since they are much easier to read
Italicize some more urls
Fix handling of events in sandbox timer