...silence a warning, quote ssh-agent results.

Uses pngphoon and i3lock.

This takes care of everything in the session being able to see the correct
$PATH material - I'd been fiddling with .profile, which is arguably where
this ought to live, but I don't think my prepend_to_path() is valid for
/bin/sh?  I'll probably tidy this up later, but at any rate it solves a
bunch of problems.

Also enables the deletion of bin/firefox-wrapper.

Uses xautolock and i3lock.

Also removes xmodmap from xmonad.start.

I've come to rely on this thing, for better or worse.  Mostly as a way
to paper over the hilariously inconsistent clipboard behavior of a modern
apps like browsers.

See:  https://twitter.com/alangrow/status/841855821671612417

...seems like a more lightweight way of providing various settings to
Gtk apps (and maybe other stuff? I'm not sure).

Various other font tweaks and such in this commit.

- messes with DPI & fonts
- changes trayer height
- rewrites chunks of xmonad.hs to use EZConfig style bindings, rofi for
  launcher and i3lock for a lock screen (thanks @benlemasurier), and a
  slightly different set of layouts.  also handles some fancy laptop keys
  like volume adjustment.  still need to steal casey & tyler's stuffs for
  backlight handling, probably.

for now, i'm going to keep these changes in a separate branch rather than
attempt to make them work on all of my systems.  I'm running Debian Stretch
on here and the monitor is giant, so it would likely be a hassle, and it's
small enough that i can probably just manage as a separate branch as long
as needed.

Getting old may beat the alternatives, but it sure is kind of shit on its
own terms in a lot of ways.

To be honest I don't even know if this worked.

So when I got home from the office, I could actually smell burning coming
out of my laptop bag. It turns out that, minus gnome-power-manager, this
thing doesn't know how to go into sleep mode when you close the lid.

It's hard for me to fully express how much I hate the idea of this stuff
being handled by a random user-space application that sits in a little
tray area. This is exactly the kind of shit we have all for years now
boggled that Windows users so blithely tolerate.

But whatever. It works.