Unbreak the exposure of error codes through the Python bindings API.
Unbreak the exposure of error codes through the Python bindings API.

* subversion/bindings/swig/core.i
  Re-org a little, and move the inclusion of svn_error_codes.h out of
  the SWIGPERL #ifdefs.

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