Trait to provide the $max (max) method as a bareword operator..
$max ("foo" -> 10)
Targets an RValue of (String, ValidNumericType)* to be converted to a DBObject
Due to a quirk in the way I implemented type detection this fails if you mix ValidNumericType types.
E.g. floats work, but not mixing floats and ints. This can be easily circumvented
if you want 'ints' with floats by making your ints floats with .0:
$max ("foo" -> 5.0, "bar" -> 1.6)