* ext/tk/tcltklib.c: avoid error on a shared object.

* ext/tk/extconf.rb: support --with-tcltkversion

* ext/tk/README.tcltklib: add document about --with-tcltkversion

* ext/tk/sample/demos-jp/widget, ext/tk/sample/demos-en/widget, 
  ext/tk/sample/demos-jp/style.rb, ext/tk/sample/demos-en/style.rb, 
  ext/tk/sample/demos-jp/bind.rb, ext/tk/sample/demos-en/bind.rb: 
  bug fix.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@15943 b2dd03c8-39d4-4d8f-98ff-823fe69b080e