Set BOOTQ before running XEX

[markjfisher]

On Fujinet project, picoboot is being used to boot applications not associated with an ATR file.

I've noticed that in my own xex files launched from there, unless I specifically set BOOTQ to 1 in the launched application, the reset handler plays up and jumps to Self Test instead of running the correct reset handler.

I traced this to BOOTQ not being set to 1 and the OS handling it different during soft reset. After going to Self Test, pressing RESET again would run the application again. So alternating between Self Test and the Application every time reset is pressed.

Rather than every application setting BOOTQ, it would be useful to set it in the loader itself before running INIT and RUN addresses.

This MR is for that change.

I've tested this on both actual hardware and through Altirra, reset handling no longer jumping to self test.

[markjfisher]

Sorry, to be able to compile this, I needed #1 to be included, so that PR can be ignored if this combined one is accepted instead.

Or I can rework the history if you prefer, but they are both minor changes.