Lovely tweaks to make more things work right, hooray

- markdown preview uses github for public files
- markdown preview uses python and github.css for private files
(think passwords saved in markdown)
- see https://gist.github.com/andxyz/8569011 OSX Mavericks specific
- apacheconf files now get syntax highlighting
- changed the open terminal keys to not overlap with command+shift+t
which undoes a tab, due to my chrome (the web-browser) muscle memory
- on that note I'm using command+shift+o to open the folder and
highlight the file in finder, more and more