Changes:
- `ShowDevelopmentWarning` is now under the '[Interface]' group in
Dolphin.ini, with other interface-related settings. So, whoever uses
DolphinQt will have to edit that manually again. Sorry!
- Game search paths and the last file are now shared properly with
DolphinWX
- Qt-only preferences like "Preferred View: list/table" are now
stored using the platform's native settings storage, rather than in
UI.ini
EndPlayInput runs on the CPU thread so it can't directly call
UpdateWantDeterminism. PlayController also tries to ChangeDisc
from the CPU Thread which is also invalid. It now just pauses
execution and posts a request to the Host to fix it instead.
The Core itself also did dodgy things like PauseAndLock-ing
from the CPU Thread and SetState from EmuThread which have been
removed.