make them private [ruby-dev:30074].
* ext/tk/lib/tk/txtwin_abst.rb: fix typo [ruby-dev:30073].
* ext/tk/lib/tk/canvas.rb (TkCanvas#scan_dragto): lack of an argument.
* ext/tk/lib/tk/canvas.rb: clarify the including module name [ruby-dev:30080].
* ext/tk/lib/tk/scrollable.rb: change primary name of modules [ruby-dev:30080].
* ext/tk/lib/tkextlib/iwidgets/checkbox.rb: wrong number of arguments
[ruby-Bugs-7776].
* ext/tk/lib/tkextlib/iwidgets/radiobox.rb: ditto.
* ext/tk/lib/tkextlib/blt/tile/checkbutton.rb: change primary name of
class [ruby-dev:30080].
* ext/tk/lib/tkextlib/blt/tile/radiobutton.rb: ditto.
* ext/tk/ChangeLog.tkextlib: update.
* ext/tk/lib/tkextlib/version.rb: update.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@11577 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
