configure.in : add --enable-setreuid option
tcltklib.c : TclTkIp.new accepts 'ip-name' and 'options'
             ( e.g. TclTkIp.new('FOO', '-geometry 500x200 -use 0x2200009') )
tk.rb      : support arguments of TclTkIp.new
             ( see TkCore::IP_NAME, TkCore::IP_OPTS )
tk*.rb     : preparations for multi-Tk interpreter support


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4127 b2dd03c8-39d4-4d8f-98ff-823fe69b080e