yob / roxml forked from Empact/roxml

A few ideas:
 
Construction:
 * xml_construct is somewhat limited in that it overrides default constructor
   arguments arguments and doesn't allow non-xml arguments
 
 * parse has room to provide non-xml initialization arguments after the initial xml argument
   but such a feature would need to integrate with xml_construct, and must settle the
   question of when to call initialize: before or after parsing.  Before and you maintain
   the standard 'initialization is called on empty objects', but you don't have the benefit of
   xml attrs to initialize with.  After and vice versa.
 
 * :as => :self for sending method_missing to this attribute
 
 * :as => :int/float  as shorthand for "do |val| Integer(val) end"