Add in and explain standard deviation. Closes #2.
Issue #37: read a single keystroke from the console
Merge branch 'master' of github.com:clojure-cookbook/clojure-cookbook
Added license file
Add license agreement and author comment.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	local-io/local-io.asciidoc
Merge pull request #51 from zclj/master

Additions to local-io and strings
Merge Pull Request #40
Merge remote-tracking branch 'origin/pull/14'
Tweak to statistics recipe
Update 'read keystroke' recipe in local-io.

Responded to Ryan's and Colin's comments.  Note that this version has a footnote which, when HTML output is produced, renders at the end of the entire HTML document (i.e. the end of the book), but which should render properly at page bottom in PDF output (which I haven't gotten working yet in my asciidoc installation).
Clarify what the standard deviation is.

Also include a link to the Wikipedia site for Standard deviation.
Fix grammatical error.
Merge pull request #52 from hyPiRion/standard-deviation

Clarify what the standard deviation is. Ref #14 and #2.
Merge #53
Update CONTRIBUTING.md to specify canonical location of recipe files
Merge pull request #61 from jcromartie/instructions

Update CONTRIBUTING.md to specify canonical location of recipe files
Adds recipe for reading/writing clojure data structures on disk
Adds read/write clojure data to Local IO chapter file
Adds note pointing to read-write-files