FAQ terminology harmonisation

[Vance Shipley]

There are good reasons for writing defensive C code.  You need
to check for memory bounds mainly.  If you didn't you'd have 
plenty of the sort of flaws which make for CERT advisories.

I don't extend the Erlang "let it fail" philosophy to my C 
driver code.  Personally I consider this interface to be 
external and code the C node to validate the input.  

	-Vance