Sgt-Puzzles: Enhanced zoom feature

[__builtin]

Hi all,

I've enhanced the "Zoom In" feature in all sgt-puzzles plugins (now in git): the viewport will now intelligently follow the in-game cursor around while in the zoomed-in state. This change should eliminate much of the need to switch back and forth between the viewing and interaction modes while zoomed; you should now be able to complete most puzzles entirely in interaction mode.

Please try this out and let me know how it works.