Remove command-T override menu shortcut

I'm not using command-T anymore so there's no need for this menu
override.
Remove NERDTree

Starting to use netrw instead. NERDTree is taking up space, and I like
that netrw is treated as another buffer.
Remove Supertab configuration.

No longer using, no need to configure.
Remove SQLUtil configuration

Another bundle no longer being used.
Switch leader to <space>

Comma was a nice leader, but <space> is even easier to get to. Adjust
ctrl-p to use <space><space> to activate. And change folding toggle to
enter, which I like a WHOLE lot better than space. I was always
confusing the two.
Ignore untracked files in submodules

Grew tired of my repository always complaining about being dirty due to
untracked files in the submodules. Mailing doc/tags which is created by
pathogen. Found this solution:

http://stackoverflow.com/questions/4343544/generating-tags-to-different-location-by-pathogen#4346300