R4481 Checkstyle Parameter Rename Issue

[Rod Widdowson]

Following up on this I entered IDP-1036 for cleanup in a future major release.

But it struck me that we might want to minimise accidental fall-out by removing any us of name constructor parameters in our public conf files.  We could do this now with no effect (except on readability).  But

1) c:_0="foo" isn't as readable as c:thing="foo"  (I think the consensus here is "tough").
2) It doesn't remove any requirements on us to keep the parameter name the same from now on.

I did a quick grep and was surprised at how many there are (about 38 uses of c: which are neither c:_0 nor c:id, plus possibly three in long hand)

What do we think?

 At the risk of further opening a rathole which I _really_ don't want to go into this feels like a case when an annotation _might_ be useful; we can annotate what is being exposed _now_ quite easily.  I guess it wouldn't be too hard to go back over the release since 3.0.0 if we felt it was worth it.

Rod