add .Append (string) overload method
add .Append (string) overload method

svn path=/trunk/gtk-sharp/; revision=17418

Gankov/gtk-sharp,openmedicus/gtk-sharp,antoniusriha/gtk-sharp,sillsdev/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,orion75/gtk-sharp,sillsdev/gtk-sharp,Gankov/gtk-sharp,Gankov/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,sillsdev/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,antoniusriha/gtk-sharp,antoniusriha/gtk-sharp,openmedicus/gtk-sharp,akrisiun/gtk-sharp,orion75/gtk-sharp,orion75/gtk-sharp,antoniusriha/gtk-sharp,akrisiun/gtk-sharp,openmedicus/gtk-sharp,Gankov/gtk-sharp,sillsdev/gtk-sharp,orion75/gtk-sharp,antoniusriha/gtk-sharp