PDF-694 attempt to correct a alpha transparency issue with a white color value.

git-svn-id: http://anonsvn.icesoft.org/repo/icepdf/trunk/icepdf@39868 8668f098-c06c-11db-ba21-f49e70c34f74
PDF-675 addition of range for the getPixel method to avoid the potential of an index out of bounds.

git-svn-id: http://anonsvn.icesoft.org/repo/icepdf/trunk/icepdf@39871 8668f098-c06c-11db-ba21-f49e70c34f74
PDF-696 adjust white detection for separation colours defined with tint values < 0.04.

git-svn-id: http://anonsvn.icesoft.org/repo/icepdf/trunk/icepdf@39872 8668f098-c06c-11db-ba21-f49e70c34f74