huffman [Wed, 14 Jan 2009 17:11:29 -0800] rev 29530
change to simpler, more extensible continuity simproc
define attribute [cont2cont] for continuity rules;
new continuity simproc just applies cont2cont rules repeatedly;
split theory Product_Cpo from Cprod, so Cfun can import Product_Cpo;
add lemma cont2cont_LAM', which is suitable as a cont2cont rule.