*::: ClassAd::sPrintAsXML() *DONE* *::: ClassAd::IsValidAttrValue() *DONE* *::: ExprTree::DeepCopy() *DONE* +*::: ClassAd::initFromString() *: Write helper functions for these methods which we can't emulate transparently *[4 hours]*: *:: ExprTree::PrintToNewStr() *DONE*
