Nothing drastic in this commit; just takes care of some little
inconsistencies and quibbles.  Probably breaks a few files with calls to
filter utilities, but those should be easy to fix on a case-by-case basis.
I'm renaming them because there's nothing vim-specific about them.

- move a few aliases to bin/
  - tags -> build-tags
  - extip -> get-external-ip
- rename some utils in bin/
  - vim-filter-* to filter-*
  - vertical to filter-vertical
- remove some bogus stuff from bin/
  - googleearth
  - d (some thing i was messing around with for menus)
  - pup (nice util, but should install elsewhere)
- add a bin/cheat to hang cheatsheet stuff on
- use fzf-tmux for h alias

fzf:

  https://github.com/junegunn/fzf

I'm not 100% sold yet, but it's basically dmenu for the shell.  Much to
recommend.  Adds an improved ctrl-r.

unsorted-unique is just a wrapper around a short awk operation.  I put it
in its own script because quoting things in aliases is hard.

It's neat; it's too opinionated.

This is way primitive, but I think a full-featured version won't actually
be much more code.

I'm still not really sold on this Oh My Zsh business.

History is still kind of weird with this.  Switches to using scd for
directory history.

These will now be subcommands of the wrt tool instead of clogging up the
general namespace for no particular reason.

Sometimes it's good to be reminded what shell you're in.

Kind of silly to have two aliases here, since they use different markers.

Possibly quite slick.

Like zsh's autocd - treat a bare directory name as `cd directory`.

https://github.com/tpope/vim-fugitive/issues/834

The idea here is that periodically you do something like:

    $ comment "messing with wifi settings"
    $ comment "trying out new file managers"

And then you've got some human-readable context in your shell history.

This is the stub of a larger, better idea, I think.

...just kinda taking it for a spin.

...I've been using this more consciously of late.  It's a decent way
to deliberately collapse sections of a file.

- zi enables folding
- `{{{` and  `}}}` denote a section

BPB_TabDrop will open a symlinked file in its canonical location, which is
better (for example) for opening a version controlled .vimrc that is
symlinked from the user's home directory.

This particular cat is pretty thoroughly vacuumed.

Moving stuff to a home/ subdirectory turns out to have been a painful
idea, because I had symlinked to a bunch of paths that went away.  This
really needs some kind of abstraction over the top of it, even if it's just
a script to manage the links.