Refactor FishingRod and Lure
Added active objects list for GameObjects that need update called
Make a separate ShapeRenderer and share a single Line batch for drawing
lines. Added a separate draw pass via drawLines() method in GameObject.

Made debugDraw() only work in debugMode which can be activated by
pressing D.

Made the Lure update() be initiated by FishingRod rather than the active
object list so that it will be updated in the correct order (after
FishingRod, so it looks right when rendered)
Slightly hacky fix to stop the rod activating once you pull the lure out
of the water, then release the mouse button.
Update Shop to use new drawLines() method
Add water line just below the top of the water (approx. at the bottom of
the troughs of the waves)
Update Lure to submerge at the water line
Update ShopButton location to be on the water line
Tweak tiling of Water texture to be seamless (remove the white vertical
line at the point where the texture repeated.)
Make ShopButton bob up and down