RE: Enlarge MAX_ALLOCA?

[Herring, Davis]

> - see if we can allocate this area less frequently (e.g. if it's for
>   handling compositions, it seems like it shouldn't be needed in your
>   cases where you encode file names (or do your file names have parts
>   that require compositions?)).  I.e. delay the allocation to when we
>   really need it.

We could also allocate it less frequently by allocating it statically (unless 
en/decoding can be reentrant, which seems unlikely).

Davis