Add another FSFS revprop packing test.  This will FAIL and a
follow-up patch will fix the problem.

* subversion/tests/libsvn_fs_fs/fs-fs-pack-test.c
  (get_set_multiple_huge_revprops_packed_fs): new test
  (test_funcs): register new test

Suggested by: zhakov

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1513879 13f79535-47bb-0310-9956-ffa450edef68
When modifying packed revprops, we may need to split the pack file to
stay within the configured file size limits.  After the split, on of
the pack files will start at a later revision than the manifest.
Splitting the same pack again will resulted in the file names being
picked from the wrong manifest entries.

* subversion/libsvn_fs_fs/fs_fs.c
  (packed_revprops_t): store the revision of the first manifest entry
  (get_revprop_packname): set that new member
  (repack_stream_open): fix the calculation of the manifest entry index

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1513880 13f79535-47bb-0310-9956-ffa450edef68