- drop unused parts (MouseQuat/GuiQuat)
- move "old-reinit-dialog" fgcommand to fg_command.cxx under new name
"reset" for now. (May later get merged with fgcommand "reinit".)
- move reInit() to fg_init.cxx: This was used by Shift-Esc and
Menu->File-Reset (via fgcommand "old-reinit-dialog"). We have already
a similar function fgReInitSubsystems() in fg_init.cxx, so these two
functions will probably get merged later.)
- it's unused
- it's hardcoded (we already got rid of all other hardcoded dialogs)
- we'll have to consider switching to osgWidget, which is planned to
get imported into osg. It's unlikely that we add *more* of PLIB
in the meantime.
