setup.html topics in standard order, with standard split

We are running a Windows heavy workshop with R and svn, and the formatting is strange because installation instructions for Git and Bash are tied together. Also noticed that the topics changed order and split for different operating systems, leading to blank columns on the left. Rearranged all topics to order:

* Bash
* Editor
* Git  
(Column Split)
* Python
* R
* SQL  

The goal is to avoid completely empty columns, which happened with our combination. Example rendered site can be seen here: http://dhavide.github.io/2014-12-09-mpac/