Support svn_client_merge_peg3().
Support svn_client_merge_peg3().

* subversion/bindings/swig/ruby/svn/client.rb
  (Svn::Client::Context#merge_peg): Use Svn::Client.merge_peg3
  instead of Svn::Client.merge_peg2.

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