(v0.8) Ch2 typos and grammar

Not too many problems anymore with Chapter 2...

2.5, First Paragraph
Footnote 3 appears twice. The one at the end of the paragraph is probably not supposed to be there anymore.

2.7, Paragraph under http://maven.apache.org
* First sentence is a bad comma splice.
* Remove "a" before "frustrating, confusing, and overwhelming."

2.7, Paragraph under Maven User Mailing List
Last line: missing colon between "here" and the URL

2.8, Second para
Last sentence typo: "Here's is". Also, seems like this sentence should end in a colon. Your call.

2.8, Last line
This last line seems unnecessary. It certainly doesn't fit with 2.8, and it's not important enough to get its own section heading. I'd say cut it. The reader will figure out the transition when he turns the page.