make a change so that the text reference to the code are consistent with code
New favicon
Remove references to trimLeft and trimRight

They are not in ES5 and not implemented by IE.
Integrate tech editing for Chapter 5
Integrate tech editing of Chapter 12
Generate index for PDF
Add missing index style file for nostarch build
Fix solution 17.2
Fix two typos

Closes #114
Ch. 16: Allow smaller canvas for smaller level
Merge remote-tracking branch 'upstream/master'