SWIG bindings: Update MERGEHASH typemap to use the %append_output() macro used by other mapping code.
SWIG bindings: Update MERGEHASH typemap to use the %append_output()
macro used by other mapping code.

* subversion/bindings/swig/include/svn_types.swg
  (MERGEHASH): Replace direct call to t_output_helper() with an
   equivalent call to the %append_output() macro.  Fix formatting.

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