Add property retrieval tests.
Add property retrieval tests.

* subversion/tests/libsvn_wc/db-test.c
  (set_prop): Tweak doc string wording to match Subversion style.
  (validate_node): Remove idefs around property retrieval
    tests. Rewrite the code to actually compile + work with the seed
    data from test_inserting_nodes(). Also, add comparisons that the
    two styles of property value retrieval produce the same result.
  (test_inserting_nodes): Drop some extraneous calls to set_prop().

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