Add brake and power rails

Once upon a time, I found myself bon a server with carts, but no Mesecons,  On another, the Mesecons didn't interface with rails, so I made these rails to fix aforementioned problems. I hope the code is of sufficient quality.

I haven't added craft recipes, but I think that power should be:

    SMS
    SWS
    SMS

S=Steel
M=Mese
W=Wooden stick.

and brakes should use something like a coal lump or some sand(as a high-friction object) in place of mese,