Settings can be changed while XQEMU is running, but aren't effective until next start of XQEMU

[JayFoxRox]

The settings dialog can be opened while XQEMU is running.
However, many of its options configure the hardware state and should not be modifiable while the Xbox is already running (Flash / EEPROM / HDD image / LPC / SMC flags / ..).

We should disable most of the settings dialog while XQEMU is running.

Settings which should still be configurable at runtime:

• Input
• DVD Image (needs to properly eject the tray via SMC first)
• Network (at least connecting / disconnecting cable)
• AV cable (warning should be displayed so user is aware that Xbox might reboot)

Ideally, all of these would have a separate UI in the main-window, as these are features that a physical Xbox exposes to a user.

Other options could be runtime configurable if supported by QEMU (can it switch to hw-virt at runtime?), however, those should probably remain in the settings window.