Respect -compress zip option in choosing jng_alpha_compression_method.
Respect -compress zip option in choosing jng_alpha_compression_method.


git-svn-id: 30845bc7fc80f5093482d603a8793ec304d98d3a@6299 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74

Distrotech/ImageMagick,Distrotech/ImageMagick,Distrotech/ImageMagick,Distrotech/ImageMagick