Remove @Deprecated ClassLoaderUtils as it's now in yangtools.util

Remove @Deprecated ClassLoaderUtils as it's now in yangtools.util

Not sure what ODL policy is re. clean up of deprecated classes, so I'm
proposing to killing one, and see what happens... ;-)
https://twitter.com/drdeprecator

More seriously, it's probably safer if critical code such as ClassLoader
related stuff is maintained in a single place, not in two copy/pasted
classes. (If we have to keep this, perhaps it could delegate to the new
one instead of copy/paste?)

Change-Id: Icac8d4f81ba102bba37e11b611874db3dea49793
Signed-off-by: Michael Vorburger <vorburger@redhat.com>