Reconstruct() using capicity() rather than limit()

See this topic:

Is there any reason for using capacity() instead of limit() for retrieving the buffer size, or can I change this to limit()? When you allocate a buffer the limit is set to capacity by default, so the only people with a problem (if this is changed) that I can see are those who for some reason changed the limit, which has no effect now anyway.

Anyway, I'll change this together with the VBO things, unless anyone knows a good reason not to.