Use a loop for testing jdk paths

Loop through a list of sensible default
locations for a JDK, stopping if a
workable JDK is found.
Also, add support for CentOS' default
java location.

Signed-off-by: Joe Buck <jbbuck@gmail.com>
Removing extraneous code

The ExternalResource code was unnecessary and caused
issues on CentOS. Removing it.
Update Makefile.am to reflect the fact that
an anonymous class was removed and its
$1.class file is no longer generated.

Signed-off-by: Joe Buck <jbbuck@gmail.com>
Remove unneeded junit4 check

We refactored the java tests to not use
the ExternalResource class, so this test
is no longer necessary.

Signed-off-by: Joe Buck <jbbuck@gmail.com>
Merge pull request #604 from ceph/wip-buck-centos-core

Wip buck centos core
Reviewed-by: Gary Lowell <gary.lowell@inktank.com>