emacs: BREAKING complete transition to use-package

prot-emacs.org: fix some bugs with incorrect symbols

UNIFY bspwm and herbstluftwm configurations

They already shared a lot, but I am now consolidating their files,
keeping their differences where necessary.

denote: sync latest updates

Refer to its repo for documentation and proper commit/change logs:
<https://git.sr.ht/~protesilaos/denote>.

Emacs, bspwm, herbstluftwm, swaywm

I did not properly track the progress after the release of tag v2.2.0.
A lot has changed since then.  In short:

+ I had quit bspwm for a few months, then switched back to it.

+ Tried Sway for a couple of weeks and kept it as a plan B or
  alternative for the inevitable Wayland future.

+ Configured herbstluftwm which is good for an ultrawide display.

Everything related to those window managers is underdocumented.

My Emacs-related contributions continues to increase in volume and
improve in quality.  Better check my website for more on the matter:
<https://protesilaos.com/emacs>.

v2.2.0 (last version with BSPWM+extras)

Latest version of my dotfiles on Void Linux

Version 2.0.0: working system on Void GNU/Linux

There have been A LOT of breaking changes since the last tagged commit
(90b190a).  Not only have I switched away from Debian, but I have also
transitioned to a full-time Emacs user.  To that end, lots of standalone
tools, like `newsboat' or `mutt' have been removed.

The changes in outline:

+ A comprehensive config for Emacs is available.  It encompasses, among
many others, packages for email (`mu4e') and RSS (`elfeed').  I have
also removed the entire MPD setup, replacing it instead with a simpler,
more elegant solution inside of Emacs (`bongo').

+ Tmux has been removed.  Same with every program that is rendered
obsolete by Emacs.

+ Vim stays but is not actively used.

+ Lots of old scripts have either been rewritten or deleted.

+ Other aspects have been considered anew, leading to the removal of
`compton' and `dunst' configurations, as well as the replacement of all
`dmenu' interfaces with `rofi'.

+ There now is a `xinit' set of configurations.  The graphical session
is launched from a TTY.  The initialisation of the X server is automatic
under certain conditions.  This supersedes older settings that assumed
the presence of a graphical Display Manager (e.g. `lightdm').

Despite these major reforms, I consider the transition to both Void
GNU/Linux and Emacs a work-in-progress.  I do, however, feel that the
present state is robust enough to merit a tagged release.

Fixes inconsistency in `tempus'

This concerned a couple of options for bspwmrc, which were not written
to the file, even though they were passed to the running session.
Changes must be stored in bspwmrc to persist.

Fixes poorly designed key in .tmux.conf

This concerns an issue where Ctrl+Shift+f was _supposed_ to invoke
a search in the scroll buffer.  Instead, tmux would pick Ctrl-f,
ignoring shift altogether.

Furthermore, the workflow of this key was cumbersome.  Upon exiting the
search, tmux would remain in copy-mode, thus requiring another key to
exit.

This key combo was added on June 30, 2019, in commit dfd7f8c.