Add test for issue #4093 'remapping a file external can segfault due to "deleted" props'.
Add test for issue #4093 'remapping a file external can segfault due to
"deleted" props'.

* subversion/tests/cmdline/externals_tests.py
  (remap_file_external_with_prop_del): New.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion