Demorgan intention

Created two intentions to convert appropriate Boolean expressions with DeMorgan's law. 

ConvertNegatedBooleanSequence changes an expression of the form "!a && !b && ... && !n" and changes it to "!(a || b || ... || n)".

ConvertNegatedExpressionWithDemorgansLaw changes an expression of the form "!(a && b && ... && n)" to "!a || !b || ... || !n".