Fix the new SVN::Wc::parse_externals_description3() tests for swig-pl.

* subversion/bindings/swig/perl/native/t/9wc.t:
  Convert the tests to using is instead of ok when looking for a value and
  isa_ok when looking for a class.  Fix the type for the revision and
  peg_revision fields since they are pointers.  Fix the symbol for accessing
  the svn_opt_revision_t enum values.  Disable the kind tests on the 
  svn_opt_revision_t values (accessing this is bugged right now).


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1444970 13f79535-47bb-0310-9956-ffa450edef68