Rearrange joystick global init order to match def order somewhat.
Initialise joy_port_[xy] to -1 so that if the port handlers are ever reinstated
for when there is no joystick and the first joystick port access is an inb,
the axis bits will be set high like the buttons (the byte returned will be 0xFF).

Update comments to emphasise Stas' r1.4 change (don't register joy port handlers
if no joy).


git-svn-id: https://dosemu.svn.sourceforge.net/svnroot/dosemu/trunk@1162 7758b857-130e-0410-ab9c-d8735a528d18