Remove the Jing fork included in epubcheck and use the latest Jing instead

epubcheck contains a fork of an old Jing (2003) that adds a few changes to 
allow setting an entity resolver that was needed to be able to resolve the 
relative references found in the schemas included inside the epubcheck jar.
The latest version of Jing supports setting a resolver directly so the fork is 
not needed. 
Also, the relative schema references point to incorrect locations, they rely 
only on the specific resolver that is set in order to be correctly located and 
also on an issue from the Jing default resolver that does not handle jar URLs 
and thus return the initial relative location to the entity resolver. The 
schemas included in the epubcheck jar should use correct relative locations so 
that if they are extracted from the epubcheck jar they should work without the 
need for a specific resolver.

Original issue reported on code.google.com by georgebina76 on 10 Feb 2011 at 12:21

daniel782 / epubcheck

Remove the Jing fork included in epubcheck and use the latest Jing instead #92