GOB: Remove useless memcpy()

Happened while removing Draw::_vgaSmallPalette in 0f9b1364c.

Fixes Coverity issue #1230309.
MADS: Minor clean up of sprite set removal
SCI: Enable some menus in Jones after restoring (bugs #6537 and #6723)

The code path that is supposed to enable these never gets called when
restoring from the main menu, or from the ScummVM launcher. Since the
logic on when and what to enable is quite complex, the easiest thing
to do is enable these entries manually after a game is loaded.
GRAPHICS: Silence an MSVC warning