[development] some performance notes

[Chris Johnson]

This review / performance improvement is well under way.

I've noticed that we could completely delete a lot of is_array() calls if we 
simply defined the argument as an array only.  It is either an array, or it 
isn't.  The caller should wrap the single element in array() if need be.

What are other opinions?

I'll fix them if we agree that's the right way to go.


..chrisxj