VESA mode: Set the viewport size correctly so the position bar does
not overlay the map.
VESA mode: Correctly set the size to which tiles are stretched when
overview mode (F4) is selected.
Both VESA and 16 color modes: Pass correct parameters to vga_userpan
and vesa_userpan, so the pan keys (CTRL+arrow) work correctly.
Some emulations don't report CTRL with up or down arrows, so accept
CTRL-home, CTRL-page up, CTRL page down and CTRL-end.
16 color mode: Set the panning direction so CTRL-left and CTRL-right
pan in the same direction as 3.4.3.
Ray Chason
1ac6ec5d1e