Add simulation of universal Turing machine

[jfinkels]

It would be nice to have an example of an Analytical Engine program that simulates a Turing machine. This would prove explicitly that the Analytical Engine is Turing-complete.

There would be some limitations.

• The Engine has a finite memory, so it could only handle 1000 states and 1000 symbols, etc.
• The user would have to explicitly specify an input string encoded as integers stored in memory using a sequence of number cards. This would mean hardcoding the memory locations of the Turing machine program and the input symbols.
• The blank symbol would need to be represented by an integer.