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This replaces the use of `variable-pitch-mode`, which prevented fixed
pitch for, e.g., code blocks.

The ucs-utils package makes Emacs shutdown much slower and back-button
can work just fine without it.

This fixes a few build warnings concerning undefined variables.

In particular, rely on some defaults set in the emacs init module.

Wasn't as much fun as I had hoped.

Instead enable them in individual configurations where they are used.

The previously used inhibit-startup-message variable appears to be
deprecated.

In particular, set the preferred date format.

Also turn off trailing whitespace visualization in vterm mode.

Some general improvements and fixes in the Emacs configuration.