Exposed the new gtkutil stock helper APIs in the header for reuse.
Swapped setup dialog stock button creation to the new gtkutil_button_new_from_stock helper (including the sound play button fallback).
Switched channel tree and theme application logic to use the new palette helper.
Updated entry and user list styling to route palette/font application through the helper.
Updated gtkutil_button() to use icon-name images on GTK3 while preserving stock image usage on GTK2.
Switched menu icon creation to the shared GTK3 mapping helper.
This solves the issue where the parent dialog is closed and then
the child dialog is used.
This is however only a partial fix:
- Many other dialogs throughout the codebase do not currently have
parent windows and need to be refactored.
- Not all window managers respect modal so users can still trigger
bugs. We can be more defensive against this but it requires more
refactoring.
Closes#2686
- Fixes#314
- Adds file extensions to sound and image browsing
- Some options no longer default to our config dir
- Always add a shortcut to our config dir
- Remove broken 'last_dir' functionality, gtk already knows recent
