Remove unzip helper and make pkg add a build dep to unzip.

That way we can simply check for unzip bin being installed and
error out if it's not, it's simpler.

--HG--
extra : convert_revision : 8fd6c5f11a54742403a16fa10c3ed1db7f12955b

templates/jasper.tmpl

@@ -15,4 +15,5 @@ long_desc="
  software has also been submitted to the ISO for inclusion in the JPEG-2000
  Part-5 standard (as an official reference implementation)."
 
+build_depends="unzip-5.52"
 run_depends="glibc-2.8"