module/world: make sure that the view doesn't go outside the world

gamecore/modules/world/camera.lua

@@ -235,6 +235,30 @@ function CameraSystem:getViewScale(id)
   return cam.scale
 end
 
+function CameraSystem:limitView(id)
+  local viewx, viewy, vieww, viewh = self:getViewCoordinate(id)
+
+  if (viewx < 0) then
+    self.views.list[id].pos.x = (self.views.width / 2)
+  end
+
+  if (viewy < 0) then
+    self.views.list[id].pos.y = (self.views.height / 2)
+  end
+
+  local worldw, worldh = self.world:getDimensions()
+
+  if ((viewx + vieww) > worldw) then
+    self.views.list[id].pos.x = worldw - (self.views.width  / 2)
+  end
+
+  if ((viewy + viewh) > worldh) then
+    self.views.list[id].pos.y = worldh - (self.views.height / 2)
+  end
+
+  self:computeCamPosition(id)
+end
+
 -- UPDATE and MOVE functions
 -- Move and update the camera system
 
@@ -249,6 +273,7 @@ function CameraSystem:moveView(id, x, y)
   self.views.list[id].pos.y = y
 
   self:computeCamPosition(id)
+  self:limitView(id)
 end
 
 function CameraSystem:computeCamPosition(id)