CQ 3589 was submitted to request permission to use JUnit 3.8.2
from Orbit.  We don't redistribute JUnit but we compile against it
and do redistribute a test support JAR (org.eclipse.jgit.junit)
that would depend upon it if someone were to develop their own
application code and also wish to write unit tests with JUnit.

Change-Id: I23b1f23e064224363585ec2f5dd62a0b4d28fb5b
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>