MRI: Init default font names to correct value (RGSS2)
tl;dr: I fucking suck at coding (fix double free)

MRI: Filesystem: A garbage collected SDL_RWops file handle
will call close on itself even if 'close' was explicitly
called on it on the script side before.
Config: Print parsing errors instead of ignoring them
Revert Disposable concept back into core

Pretty much a revert of
e858bbdcf5cc8120dd169d7efb8ae8d13ab0b5c5.

We need this in core to properly implement F12 reset.
WindowVX: Initialize all dirty flags and connect tmp tone
Input: Fix default keybinds
Implement F12 game reset (MRI only)

Can be disabled with "enableReset=false".

While at it, also replace the flakey volatile bool flags
with proper atomics.
RGSSError is a subclass of StandardError
Tilemap/VX: Ensure proxy objects don't outlive their parents

Either of these would previously crash (same for VX):

tm = Tilemap.new
at = tm.autotiles
tm = nil
GC.start
at[0] = Bitmap.new(1, 1)

tm = Tilemap.new
at = tm.autotiles
tm.dispose
at[0] = Bitmap.new(1, 1)

Funnily, this makes RMXP itself crash too, but crashing is
never acceptable except for possibly resource exhaustion.