Error messages are displayed using the following methods:
* **zenity** parses pango markup and replaces escaped characters
* **kdialog** replaces (some) escaped characters
* **gtk-dialog.py** replaces `\n`
* **printf** interprets format strings and replaces escaped characters
* **echo** just displays the text
The error messages themself contain escaped characters and paths from variables.
This PR unifies the behavior by:
* Use **printf** to format error messages and replace escaped characters
* Setting `--no-markup` for **zenity** to disable pango markup and escaped characters
* Remove `\n` replacement from **gtk-dialog.py**.
* Use plain **echo** instead of **printf**
This explicitly tells KDE to associate the OpenRA window with
the integrated appimage desktop file, allowing it to use the
correct resolution icon for the task switcher.
A few small improvements:
* The type `desktop` was renamed to `desktop-appliaction` (a long time ago)
* Add `launchable` to tell how the application can be launched
* Use `https` for homepage link
* Add link to the bugtracker
* Update `oars-1.0` to `oars-1.1`
* Remove all unnecessary `content_attribute` entries with value `none`
- Shared helpers extracted to functions.sh for use by upstream packaging,
Mod SDK, and downstream packaging (via the Makefile targets).
- Assembly management separated from data and combined between engine
and mods to prepare for pending .NET core requirements.
- Streamline Makefile targets.
- Clean up a lot of old technical debt.
- Use SDL2 message boxes instead of Winforms.
- Use a proper project instead of compiling a single file.
- Use assembly attributes instead of modifying strings in the source code.
- Remove generic OpenRA.exe launcher.
- Replace MakeLAA.exe with a python script.
