fix for issue #3
fix issue #4
fix issue #7
Some adaptations for OSX.

This assumes TeX Live. Running "make -f makefile.osx pdf" still
requires you to answer "R" to run without interruptions whenever it
finds a \footnote containing a \url.
fix issue #6
fix issue #5
Typo: 4.5.4 The NLS Editor
(cherry picked from commit 57ea80b8fc19fa096a3b8a0bf8950514bd62b32c)
fixed grammatical errors

fix for issue #8
fix for issue #9
Merge pull request #10 from McPringle/master

fixed grammatical errors
fixed more grammatical errors in chapter 4
Merge pull request #11 from McPringle/master

fixed more grammatical errors in chapter 4
compile error corrected

too much parentheses
grammatical corrections
Merge pull request #12 from McPringle/master

corrections for chapter 5