* subversion/bindings/swig/include/proxy.swg: Restore compatibility with    older Pythons by restricting abstract base class usage to versions that    support them (>= 2.6).
* subversion/bindings/swig/include/proxy.swg: Restore compatibility with
   older Pythons by restricting abstract base class usage to versions that
   support them (>= 2.6).



git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@908153 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion