move reader code into frontend/apps/reader

it makes more sense to completely separate the UI framework and
application code

also move frontend/ui/configurable.lua to frontend/configurable.lua

frontend/apps/reader/modules/readerflipping.lua

@@ -0,0 +1,44 @@
+local InputContainer = require("ui/widget/container/inputcontainer")
+local LeftContainer = require("ui/widget/container/leftcontainer")
+local ImageWidget = require("ui/widget/imagewidget")
+local GestureRange = require("ui/gesturerange")
+local Device = require("ui/device")
+local Geom = require("ui/geometry")
+local Screen = require("ui/screen")
+local Event = require("ui/event")
+
+local ReaderFlipping = InputContainer:new{
+    orig_reflow_mode = 0,
+}
+
+function ReaderFlipping:init()
+    local widget = ImageWidget:new{
+        file = "resources/icons/appbar.book.open.png",
+    }
+    self[1] = LeftContainer:new{
+        dimen = Geom:new{w = Screen:getWidth(), h = widget:getSize().h},
+        widget,
+    }
+    if Device:isTouchDevice() then
+        self.ges_events = {
+            Tap = {
+                GestureRange:new{
+                    ges = "tap",
+                    range = Geom:new{
+                        x = Screen:getWidth()*DTAP_ZONE_FLIPPING.x,
+                        y = Screen:getHeight()*DTAP_ZONE_FLIPPING.y,
+                        w = Screen:getWidth()*DTAP_ZONE_FLIPPING.w,
+                        h = Screen:getHeight()*DTAP_ZONE_FLIPPING.h
+                    }
+                }
+            }
+        }
+    end
+end
+
+function ReaderFlipping:onTap()
+    self.ui:handleEvent(Event:new("TogglePageFlipping"))
+    return true
+end
+
+return ReaderFlipping