Relativize github links in README.md

This helps links work even in contributor's forks.

See: https://github.com/blog/1395-relative-links-in-markup-files
Discourage the use of RailsInstaller on Mavericks -- it won't work

Use 'rvm install 2.0.0 --autolibs=disable' to install a ruby on Mavericks.

Rename 'OSX Lion' to 'OSX RVM'
Show fancy logos on 'choose OS' page
Tell Mavericks users to install homebrew and use it for rvm autolibs

This reverses my horrible mistake of thinking people on mavericks
didn't need autolibs. If you do '--autolibs=disable' it fails with
an ssl error on 'gem install ruby'. guh.
Add a request cycle overview to the int curriculum
Fix spacing in 'CRUD' explaination