* ext/tk/lib/tkextlib/itcl : add [incr Tcl] support
* ext/tk/lib/tkextlib/itk  : add [incr Tk] support
* ext/tk/lib/tkextlib/iwidgets : midway point of [incr Widgets] support
* ext/tk/sample/tkextlib/iwidgets : very simple examples of [incr Widgets]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@6602 b2dd03c8-39d4-4d8f-98ff-823fe69b080e