Filters and Functors

Modules
	Functors for building compex queries.
	Some logical functors to build more complex queries:
	ACTIONFUNCTOR
	Collection solvable filter functors.
	All functors should be able to process Solvable as well as PoolItem.
	Filter functors operating on ResObjects.
	A simple filter is a function or functor matching the signature:

Namespaces
	zypp::functor::functor_detail
	An unary functor forwarding to some other _Functor &.

Detailed Description