Move away from the whitespace-cleanup-mode package, and instead simply
define our own whitespace-cleanup-on-save-mode minor-mode that uses a
before-save-hook.
Relying on file notifications to detect changes on disk and auto-revert
buffers seems unreliable on macOS, so let's disable the use of file
notifications, and let auto-revert-mode use polling instead.
This allows specific major-modes to disable hl-line-mode, which is
desired some terminal/shell modes like vterm where the hl-line flickers
constantly while typing.
Due to the value being set not ending with a slash, auto-save files were
being stores in `~/.emacs.d/cache` instead of
`~/.emacs.d/cache/autosave`.
The fix was to add a slash at the end, and also to ensure the directory
exists.
And get rid of:
- dash, doesn't need to be, packages which depend on it, should have it
listed as a dependency
- smart-mode-line, don't need it anymore as I use the doom-modeline
package to stylize the modeline.
The core setup files for Emacs Siren which lives in the core directory
followed a `siren-*.el` naming convention, which is the same as the
naming convention for modules.
This means that the `modules/core/siren-packages.el` module for adding
packages for Emacs package development, was not being loaded due to it's
name conflicting with `core/siren-packages.el` which sets up and
configures the packaging system.
So all files under the root `core` directory now follow a
`siren-core-*.el` naming scheme, meaning modules should no longer
conflict with core files.
