Add a command to open a .snippets.py for the current filetype.

This introduces a command called `EditSnippets` to open the
corresponding .snippets.py file for the current filetype.
Add a .snippets.py template for use with the skel.
Set makeprg from .snippet.py files.

This allows the `:make` command to build the new .snippets file.
Add mappings to easily change the action during an interactive rebase.
Setup shellpipe to keep Vim from hiding failures.

This only handles bash and zsh.
Restart syntax highlighting in Python from the start of the file.

The syntax highlighting for Python was getting out-of-sync often and
causing incorrect highlighting.
Add a SetupShell.

It turns out that syntax highlighting for shell languages can get lost
quite often, so some extra setup is necessary for them.
Add highlighting of diffs in emails.

Very useful for Open Source development and working with patches via
email.  You can get a false positive, but in the past two years of using
this setup, I've only hit it once.
Reuse the current window when opening a new file.

Without this, CtrlP defaults to opening the new file in a split--which
is jarring.
Disable Powerline in 8-color terminals.

Powerline looks awful on such terminals.
Treat .syntastic_c_config files as vim.
Add a template for .syntastic_c_config files.

This makes it a little easier to add include paths relative to the
.syntastic_c_config file.
Add an AddTags() function for use within .lvimrc files.

I find myself tagging the /usr/include area (or at least portions of
it) and the kernel tree for use in other projects.  This lets me keep
the tags in a useful location, and add them in as I need them for
projects.
Remove redundant mappings that consume valuable keys.
Merge branch 'add-snippet-helpers' of https://github.com/jszakmeister/vimfiles
Note addition of ``EditSnippets`` command.
Merge branch 'add-interactive-rebase-mappings' of https://github.com/jszakmeister/vimfiles
Note new Git rebase mappings.
Merge branch 'setup-shellpipe' of https://github.com/jszakmeister/vimfiles
Note shellpipe setup.