Refactoring and flexibility changes

* Split game module into game and game_interface
* Move core_lib to corelib
* Move miniwindow to corelib
* Introduce init.lua script for initializing the client, giving much more flexibility
* OTClient is no longer Application derived and is much simpler

modules/game_interface/widgets/uiitem.lua

@@ -0,0 +1,81 @@
+function UIItem:onDragEnter(mousePos)
+  if self:isVirtual() then return false end
+
+  local item = self:getItem()
+  if not item then return false end
+
+  self:setBorderWidth(1)
+  self.currentDragThing = item
+  Mouse.setTargetCursor()
+  return true
+end
+
+function UIItem:onDragLeave(droppedWidget, mousePos)
+  if self:isVirtual() then return false end
+  self.currentDragThing = nil
+  Mouse.restoreCursor()
+  self:setBorderWidth(0)
+  return true
+end
+
+function UIItem:onDrop(widget, mousePos)
+  if self:isVirtual() then return false end
+
+  if not widget or not widget.currentDragThing then return false end
+
+  local item = widget.currentDragThing
+  local toPos = self.position
+
+  local itemPos = item:getPosition()
+  if itemPos.x == self.position.x and itemPos.y == self.position.y and itemPos.z == self.position.z then return false end
+
+  if item:getCount() > 1 then
+    GameInterface.moveStackableItem(item, toPos)
+  else
+    g_game.move(item, toPos, 1)
+  end
+
+  self:setBorderWidth(0)
+  return true
+end
+
+function UIItem:onHoverChange(hovered)
+  UIWidget.onHoverChange(self, hovered)
+
+  if self:isVirtual() then return end
+
+  local draggingWidget = g_ui.getDraggingWidget()
+  if draggingWidget and self ~= draggingWidget then
+    local gotMap = draggingWidget:getClassName() == 'UIMap'
+    local gotItem = draggingWidget:getClassName() == 'UIItem' and not draggingWidget:isVirtual()
+    if hovered and (gotItem or gotMap) then
+      self:setBorderWidth(1)
+    else
+      self:setBorderWidth(0)
+    end
+  end
+end
+
+function UIItem:onMouseRelease(mousePosition, mouseButton)
+  if self.cancelNextRelease then
+    self.cancelNextRelease = false
+    return true
+  end
+
+  if self:isVirtual() then return false end
+
+  local item = self:getItem()
+  if not item or not self:containsPoint(mousePosition) then return false end
+
+  if Options.getOption('classicControl') and
+     ((Mouse.isPressed(MouseLeftButton) and mouseButton == MouseRightButton) or
+      (Mouse.isPressed(MouseRightButton) and mouseButton == MouseLeftButton)) then
+    g_game.look(item)
+    self.cancelNextRelease = true
+    return true
+  elseif GameInterface.processMouseAction(mousePosition, mouseButton, nil, item, item, nil, item) then
+    return true
+  end
+  return false
+end
+