On Windows, Qt's default system font (MS Shell Dlg 2) is outdated.
Dolphin previously used over 15 lines of code to compute a font
closer to the proper font, but with an approximately correct font size.
Using the QMenu font directly is both more concise and more elegant
(in my opinion).
https://bugs.dolphin-emu.org/issues/11888
This also includes another change: DolphinQt will now exit with an
error if you use --batch without specifying a game using any method
(unlike in the past where --batch would be ignored if you didn't
specify a game using --exec, even if you had used --nand-title).
The main reason why I did this was because coding the alternative
(ignoring --batch) would be annoying with render to main involved.
Lessens the amount of files that have to be recompiled if
ConfigManager.h is modified. This also removes an indirect inclusion
within DolphinQt/Main.cpp.
* Confirm stopping emulation when the window is closing, not just the "Stop" button
* Don't resume if we were already paused when we got the quit event
* Shutdown the core at the end of main() so we don't crash on exit
* Miscellaneous other logic cleanups related to this
The UI should decide on where it wants the user directory, not our core system.
This is in anticipation of some upcoming work on Android which will need proper user directory setting.