A couple of tiny ccl fixes, external-format and gitgnore for ccl fsl files.

Yes, using the keyword directly is fine in sbcl too. 

external-format is implementation dependent I think, and I don't currently have any other lisp environments to check against. Putting it in a defun like that was a deliberately temporary kludge to isolate it. However, perhaps some abstraction around it will aid portablility? ( I am not an expert in porting )