Continue loading themes with missing fonts
Continue loading themes with missing fonts

* Even though it'll probably look like :faeces emoji:.
* Prompt the user about it first.
* Reset the theme chooser combo box text if we're returning early.
  * No more "Custom" if a font is missing but the theme wasn't loaded.

mwerle/EDDiscovery,jthorpe4/EDDiscovery,jgoode/EDDiscovery,mwerle/EDDiscovery,jgoode/EDDiscovery