emacs: Optional dependencies (d-bus, glib, librsvg, imagemagick)

New optionals:

 - d-bus for notifications
 - glib in HEAD (used for file notifications).
 - librsvg for SVG support
 - imagemagick for image viewing and manipulation

Closes #30515.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
wine --devel 1.7.22

Closes #30838.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
No need to cache lookup that is only done once
Use a hash to cache compiler version lookups
CONTRIBUTING: link to PR guide.
mercury 14.01
mercury: update 14.01 bottle.

Closes #30530.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
CONTRIBUTING: fix dashes.
Use accessor method in test
verliator 3.862
nudge formatting

Needed for Emacs' ruby highlighting to work past this point in the file.
Inline method that just wraps a constant
Inline method so we don't merge and unpack options twice
Remove default value from bottle_suffix parameter

We always call this method with an argument, so we can simplify it.
Remove default value from bottle_url options parameter

To construct a URL, we need options to pass to bottle_filename, so this
method should error out if none are given.
luvit 0.8.2

Closes #30840.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
LibreSSL 2.0.1

Closes #30817.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
libressl: add 2.0.1 bottle.