Minicore: Correct colors in NPC images

The problem was caused by the resizing of the npc images
from fantasycore in fb5ca779b5f23839737af41fb965736efb5fb54e

The transparent color is just invisible pink (R=255,G=0,B=255,alpha=0).
When these transparent pixels were merged into some
visible pixels, the invisible pink part lead to wrong
results when merging the pixels.

The resize and packing script was corrected here
https://github.com/stefanbeller/RectangleBinPack/commit/061aa46d7ed34ae5c9e87e4fcabe80c5234d60dc

The generation of the noalpha version was done as in
20086c6b9230acb36e3e038df152aef7e085375d

Though the images have been copied from fantasycore and
then fully repacked, there are no changes in the animation
definition files. Some graphics are also unchanged, which were
already correct.

This fix was tested for both noalpha=True/False

It resolves the issue at
http://opengameart.org/forumtopic/bug-minicore-graphical-artifacts
Merge pull request #293 from stefanbeller/branch0.18

Minicore: Correct colors in NPC images