On the fsx branch: constify the input value to of svn_priority_queue__push
to make the API easier to use.

* subversion/include/svn_sorts.h
  (svn_priority_queue__push): accept constant element values

* subversion/libsvn_subr/sorts.c
  (svn_priority_queue__push): update

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx@1508492 13f79535-47bb-0310-9956-ffa450edef68
On the fsx branch:  Add a test for our priority queues API.

* build.conf
  (priority-queue-test): new target
  (__ALL_TESTS__): register the new target

* subversion/tests/libsvn_subr/priority-queue-test.c
  (): new file

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx@1508496 13f79535-47bb-0310-9956-ffa450edef68
On the fsx branch:

* subversion/tests/libsvn_subr
  (svn:ignore): ignore binaries of new tests

git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/fsx@1508497 13f79535-47bb-0310-9956-ffa450edef68