Change type ID parameter in BlockPhysicsEvent to Material

After the Minecraft 1.7.2 update, this event became broken after one of its
parameters changed, and the resulting parameter passed to this event was
actually a global variable which never changed, resulting in
the changed type id returning an erroneous number.

This commit fixes that by adding the correct constructor taking a
Material. The previous constructor has been left. Failure to switch to the
new constructor will result in the event not firing as the Implementation
uses the new constructor.