rst2ctags: replace the docutils-based version with a custom one

The docutils-based version was simply too slow on large documents.  This
new one is considerably faster and reduces the lag when using TagBar
with a large document.
Provide shorter names for most modes in Powerline's mode indicator.
Merge branch 'powerline-short-indicators' of https://github.com/jszakmeister/vimfiles
Promote tagbar support for .rst files to core.
user/jszakmeister: turn on indent guides

Get rid of my custom python setup, since indent guides are in the core
now.
user/jszakmeister: drop setting up the colorscheme

It's the default now, so there's no need for it.
user/jszakmeister: drop company-related bits

I've moved them to a separate plugin at work.
user/jszakmeister: implement a better algorithm for finding sniputil

Update my snippet template to match.
user/jszakmeister: drop the unity snippets

I'm moving them to a separate plugin so others can have them too.
user/jszakmeister: no longer need autocmd for reset cursor in man pages

This was fixed a while back, but I never took out my workaround.
user/jszakmeister: remove unused function
user/jszakmeister: add some markdown snippets

One unexpected quirk here is that in order to match how reStructuredText
is done, h1-h4 don't correspond to actual h1-h4.  Instead, it's more
like h2-h5.  I may have to reconsider that later, but that's the way it
is for now.
user/jszakmeister: don't print the commands when building snippets
user/jszakmeister: add a markdown snippet for code blocks on GitHub