add screwdriver rotation handling on most pipes-related nodes

caveats:  in order to cleanly handle the entry panel, valve, and sensor
I had to rotate the valve and sensor models 90 degrees
so that their in-/outlet pipes point the same direction as the
entry panel.

This also enables proper handling of a valve or sensor turned vertically.

Some objects have rotation disabled entirely (as flipping them over/around makes
no sense)

When a valve is rotated, it is turned off automatically, to work around a glitch in
the rotation code.

pipes.lua

@@ -80,7 +80,8 @@ for index, connects in ipairs(cconnects) do
 		end,
 		after_dig_node = function(pos)
 			pipeworks.scan_for_pipe_objects(pos)
-		end
+		end,
+		on_rotate = false
 	})
 	
 	local pgroups = {snappy = 3, pipe = 1, not_in_creative_inventory = 1}
@@ -110,7 +111,8 @@ for index, connects in ipairs(cconnects) do
 		end,
 		after_dig_node = function(pos)
 			pipeworks.scan_for_pipe_objects(pos)
-		end
+		end,
+		on_rotate = false
 	})
 	
 	table.insert(pipes_empty_nodenames, "pipeworks:pipe_"..index.."_empty")
@@ -134,6 +136,8 @@ if REGISTER_COMPATIBILITY then
 		after_place_node = function(pos)
 			pipeworks.scan_for_pipe_objects(pos)
 		end,
+		on_rotate = false
+
 	})
 	minetest.register_node(cloaded, {
 		drawtype = "airlike",
@@ -145,6 +149,8 @@ if REGISTER_COMPATIBILITY then
 		after_place_node = function(pos)
 			pipeworks.scan_for_pipe_objects(pos)
 		end,
+		on_rotate = false
+
 	})
 	for xm = 0, 1 do
 	for xp = 0, 1 do