Further refactoring

This should finish the work to make all globals to local variables.
That allows LuaJIT to properly compile things by interning the
references to the relevant parts (rather than looking up globals
all the time which stops a trace).

frontend/ui/reader/readermenu.lua

@@ -7,6 +7,8 @@ local GestureRange = require("ui/gesturerange")
 local Geom = require("ui/geometry")
 local Event = require("ui/event")
 local Screen = require("ui/screen")
+local Menu = require("ui/widget/menu")
+local InfoMessage = require("ui/widget/infomessage")
 local _ = require("gettext")
 
 local ReaderMenu = InputContainer:new{