Make `rcfiles relink` report success/failure

In addition to properly reporting whether or not it was able to do
everything it is intended to do, the `relink` subcommand is now also
more explicit in what it's doing at any given time, or if it doesn't do
anything at all. This is much more like the other `rcfiles` subcommands.
Rename gitconfig to autoconfig, add new autoconfig

The former `rcfiles autoconfig` command has been more accurately renamed
to `rcfiles gitconfig`. The new `rcfiles autoconfig` command runs
through *all* configuration steps, and is primarily intended to be
called as a side effect of installing or updating (hence, "auto").

As a result, `relink` is no longer directly called by `update` or by the
installer script, because it falls under the `autoconfig` umbrella now.
Clarify docs on `rcfiles status`

This just reads a little bit better to me now, and should hopefully
describe better what I mean.
Add a command to quickly reload $MYVIMRC

I do this a surprising amount, such as when I'm testing new settings,
and so it made sense to add a command (in this case, `<Leader>rc`) to
accomplish the task.
Revert some Steve Losh-inspired search settings

It turns out I didn't really care for these particular settings - I
start off searches far too often and then erase the string for this to
work out - it just winds up costing me keystrokes. Also, the
Vim-specific regex is somewhat better suited to searching code than I
gave it credit for - "$" not being a default special character is of
particular use, and now that I've gotten used to it, having to remember
to escape it every time I want to search for a Bash/Perl variable is
tedious.

Also, global replacement is another thing I've just gotten used to, and
much like disabling <Esc> was ultimately a bad idea cause it broke with
standard configuration on most default installations of Vim, changing it
here means I won't remember what's happening elsewhere, or vice-versa.
It's just more confusing than it's worth for me.
Populate the location list from Syntastic by def.

I'll probably add some shortcuts soon, but in the meantime, this allows
me to navigate to errors caught by Syntastic with the :lprev and :lnext
commands, which is handy. The reason it isn't on by default is that it
could conflict with other plugins that want to use the location list,
but I don't think I've got any of those at the moment, so we should be
pretty safe here.