Makes a world of difference for things like vimwiki.

...one of those scripts that exists purely as a reminder that i can do a
thing.

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.

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

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

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.