locking any potential future OSD to these.
Options inheritance now is
core_options
emu_options
cli_options
osd_options
[sdl|win]_osd_options
This required a number of minor changes to other code as well.
Tested on linux-sdl, windows-sdl, windows-mainline, osx-sdl
The previous version just exhibited any member of osd_interface to the
core. This one limits core access to osd to those functions originally
specified.
There is room for improvement going forward here in the design. Left
FIXMEs where appropriate. (nw)