Sub Sinker updated

[francisferrill]

Changes,

-Rocks on ocean floor are darker. So are the charges.
-Optimized the edge detection, resulting in a slightly smaller file and smoother play.
-You can now move the ship in the scroll between levels, setting up position for he upcoming level.
-You no longer hear the sonar pings between levels, but now only when subs are present.

This has been fully tested and played through (not easy) and is up at YoYo.