Support svn_client_update3().
Support svn_client_update3().

* subversion/bindings/swig/ruby/svn/client.rb
  (Svn::Client::Context#update): Use Svn::Client.update3 instead
  of Svn::Client.update2.

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