Draft copy tool

The copy tool copies a train to a global clipboard.  It copies
the Line number, Routing code, inside text and outside text.
It copies the kinds of wagons in the train and whether they
are flipped around.

Pasting with the copy tool will conditionally flip the train
such that 'your front' of the train, rather than the absolute
front of the train, is what is output. The new train is
oriented to travel forward with the placing player's view.

Conditons are:
- Multi-unit/push-pull train (= has locomotives on both ends):
  Never flipped
- Locomotive-hauled train (= has one end with a locomotive):
  Flipped so that the locomotive is always at the front. If the
  locomotive points long hood forward, it will still point long
  hood forward.
- Rake of wagons (= has no locomotives on ends):
  Flipped according to which end of the train the p-- ars.lua
-- automatic routesetting

--[[
	The "ARS table" and its effects:
	Every route has (or can have) an associated ARS table. This can either be
	ars = { [n] = {ln="<line>"}/{rc="<routingcode>"}/{c="<a comment>"} }
	a list of rules involving either line or routingcode matchers (or comments, those are ignored)