Fix cheat scheet URL
Merge pull request #1524 from bolshakov/notes-typo

Fix cheat scheet URL
Fixed install for nokogiri on fedora 18.
Merge pull request #1525 from jrgifford/fixing-centos-fedora-dependencies

Fixed install for nokogiri on fedora 18 and CentOS
extra fix for default loading, fix #1520
Merge branch 'master' of github.com:wayneeseguin/rvm