Warn at configure time about bitmap-later

It's superseded by DAFS and is slated for removal post-1.8.

Change-Id: Id2c870fb76eeb470bbf393e99654df434b1a1a86
Finish deorbiting libjuafs.a

Change I2074d5bc26e326db36b16e055431818ef1c69210 removed the separate
compilation/link of a libjuafs.a (since it was functionally identical
to the libuafs.a already being built), but retained a libjuafs.a in
TOP_LIBDIR for use by src/JAVA/libjafs/.

This commit adjusts src/JAVA/libjafs to refer to libuafs.a directly,
and removes references to libjuafs.a which are no longer relevant.

Change-Id: I0d02ea9e4be773ac50a04925c45e5f243650e21a