More STFReader changes - the end is now in sight.
This just brings the block functions in line with the item functions.
And moves some units out of the locomotive classes into STFReader.
I have also moved the non-standard (see imperial) Steam units, into the SteamLocomtive class taking them out of the more general Wagons which should use metric.
git-svn-id: http://svn.uktrainsim.com/svn/openrails/trunk@423 a9f3cfff-6c41-7446-b0ca-052bd761e6eb