Add BigInt note to arithmetic section
Resolve issue #34, add parse-json, and resolve issue #37, change to global-growth
Resolve issue #38, change to global-growth.core ns
Remove note about cutting ns section
Clarified the Organization section that ns is already in the file.
updated wording for setup_osx.md
Merge pull request #46 from kpfell/heroku-installation-correction

Updated wording for setup_osx.md
moved period outside parentheses
updated paragraph on concurrency
added an also
updated paragraph on parentheses in Clojure
switched a colon to a semicolon
updated first paragraph about the REPL
clarified second paragraph about the REPL
added quotes in the third paragraph about the REPL
added code formatting in basic arithmetic exercise
replaced colon
added an and
changed spacing around em dashes
Merge pull request #48 from kpfell/intro-to-clojure-corrections

"Intro to Clojure" modifications