Corrected mistake in bounded lattice definitions.
Lattice laws (for all kinds of lattices).
Qualified the law names to avoid using the same name for different properties.
Helpers Bounded[Join/Meet]Semilattice.[isZero/isOne].
Merge pull request #322 from denisrosset/topic/lattice-laws

Laws for lattices, including a bug fix for the definition of bounded semi-lattices