This way dependencies are described by the MANIFEST.MF,
and the same build tools can be used to compile the tests.

Change-Id: I4dc926148410ecbadcf71b9474aeeb509691aa32

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c8a08740a9e02c421469e5b1a9e47cb.

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