sprites: Minor sprite fixes.

There are a couple of floating pixels away from the sprite that don't
appear to be part of it in : SKELC2F8 & SKELC4F6 & SKELC5F5 & SKELC6F4
& SKELG2 & SKELH2 & SKELI4 & SKELK1. They were removed.

White pixel in the bottom left corner of POSSE3E7 & POSSF4F6. White
pixel top left in POSSH0. Recoloured 'white' blood pixels to shades of
red in POSSI0.

Removed out of place white pixels in TROOD4D6 & TROOD5 & TROOE5 &
TROOF5 & TROOG4G6.