Added explicit exposition on half-open nature of list indexes
Added link to documentation on lists
Remove git lesson mistakenly attributed to The Hacker Within.
Add Matt's original git and GitHub lesson notes.
Add header material and author to git and GitHub lesson.
git -> Git where appropriate
Merge pull request #133 from jiffyclub/fix-git-and-github-lesson

Fix git and github lesson
Merge remote-tracking branch 'wltrimbl/half-open' into gh-pages

Actually, I merged origin/pr/95, because:

  git://github.com/wltrimbl/bc.git half-open

doesn't seem to exist anymore ;).

Minor quibbles to be resolved later:

* '--' vs. a Unicode em-dash (U+2014 EM DASH), but I'm not sure how
  IPython handles charsets/encodings.
* Bold vs. italics in "elements returned **include** the **starting**
  index but **exclude** the **final** index", because I like:

    * Bold to pick out key terms (page-level emphasis)
    * Italics to stress phrases (sentence-level emphasis)

Neither of those are important enough to keep this out of the main
branch.

* wltrimbl/half-open:
  Added link to documentation on lists
  Added explicit exposition on half-open nature of list indexes
Set up new Wildcards section.  Text copied from Pipes and Filters for now.
Removed copied text so that Wildcards section is blank and ready to be filled.
modified _includes/guide-shell/create/lesson.html

starting a subsection on touch

+ added more to the section on touch
+ added back in ls command line example
Put in missing </code>.
Took out the text box Quickly create and modify, and started changing things at that point.
Put ls output on one line.
Changed some text explaining touch command.
Finished changing text about touch.  Have to update the rest of the Creating Things section to be consistent.
Continued modifying section to be consistent with presence of draft_empty.txt file.
rm the draft_empty.txt file as well.
Further improvements to shell example

Changed nano to touch in a few places.

Changed wording of one sentence.
Change in wording.
Added summary bullet point about touch.
Slight change in wording to touch bullet point.
Change in wording last modification time --> time of last modification.
Added ls file* example in Wildcard lesson.
Added in examples with {} and ? wildcards.
Added negation wildcard example.