Merge pull request #1 from jdeisenberg/master

First commit of code from chapters 6-12 (unedited and not re-tested)
initial add 2-5
Renamed directories to match the text in Chapter 9.
	renamed:    code/ch09/ex3-dbg/drop.ex -> code/ch09/ex2-debug/drop.ex
	renamed:    code/ch09/ex3-dbg/mph_drop.ex -> code/ch09/ex2-debug/mph_drop.ex
	renamed:    code/ch09/ex4-dbg/fact.ex -> code/ch09/ex3-debug/fact.ex
Change to add testing for assert_raise in chapter 9.
Matched chapter 10 example files to match the narrative; changed all recordDrop.ex to record_drop.ex.