Add jGit license block to derrived tests

Add the jGit license block to tests derrived from jGit as per the
terms of the BSD license.

Conflicts:
	src/pqueue.c
	src/pqueue.h
	src/util.c
	tests-clar/merge/setup.c

The usage of the Android derrived code contains a full notice
which must be provided with the source code as per the terms
given at:
https://android.googlesource.com/platform/bionic/+/android-4.0.3_r1.1/libc/bionic/dirname_r.c

The original BSD glibc code contains the notice as given at
http://opensource.apple.com/source/gcc/gcc-5666.3/libiberty/bsearch.c
and should be given in full along with the code.

* gen_pktline() in smart_protocol.c was skipping refspecs that deleted
  refs that were not advertised by the server.  The new behavior is to
  send a delete command with an old-id of zero, which matches the behavior
  of the official git client.
* Update test_network_push__delete() in reaction to above fix.
* Obviate messy logic that handles missing push_spec rrefs by canonicalizing
  push_spec.  After calculate_work(), loid, roid, and rref, are filled in with
  exactly what is sent to the server

The original libpqueue file were licensed under Apache 2.0 so
therefore should retain their copyrights and header as per the
license terms at http://www.apache.org/licenses/LICENSE-2.0

MERGE_HEAD contents iterator

Fix bug in gen_pktline() for deletes of missing remote refs

Inline convention

Add Brian Downing to the hall of fame

License Compliance Audit

The usage of the Android derrived code contains a full notice
which must be provided with the source code as per the terms
given at:
https://android.googlesource.com/platform/bionic/+/android-4.0.3_r1.1/libc/bionic/dirname_r.c

The original BSD glibc code contains the notice as given at
http://opensource.apple.com/source/gcc/gcc-5666.3/libiberty/bsearch.c
and should be given in full along with the code.

* gen_pktline() in smart_protocol.c was skipping refspecs that deleted
  refs that were not advertised by the server.  The new behavior is to
  send a delete command with an old-id of zero, which matches the behavior
  of the official git client.
* Update test_network_push__delete() in reaction to above fix.
* Obviate messy logic that handles missing push_spec rrefs by canonicalizing
  push_spec.  After calculate_work(), loid, roid, and rref, are filled in with
  exactly what is sent to the server

The original libpqueue file were licensed under Apache 2.0 so
therefore should retain their copyrights and header as per the
license terms at http://www.apache.org/licenses/LICENSE-2.0

expose merge metadata cleanup

Mark fake home directories that failed to be created, so we won't
try to remove them and have cleanup just use p_rmdir.