Added CodeCombat.com to interactive tutorials
Merge pull request #1231 from grogy/codecombat

Added CodeCombat.com to interactive tutorials
Add CppKoans. Closes #1199
Merge pull request #1232 from sru/master

Add CppKoans. Closes #1199
elisp book
Merge pull request #1233 from johand/elisp_book

elisp book