BISERVER-7619 - Remove pngfix.js

What was done:
1) removed the file
2) searched for all the places where it was used -- nothing found
BISERVER-10784 - PUC broken with Chrome 31 & 32
Merge pull request #1197 from jeffreythomas/dev

BISERVER-10784 - PUC broken with Chrome 31 & 32
Merge pull request #1195 from kolinus/BISERVER-7619

BISERVER-7619 - Remove pngfix.js