Sections 2, 4

Section 2: Inserted short note on the scaling group, modular
automorphism group, and unitary antipode on the algebraic level.

Section 4: Included construction of the scaling group, modular
automorphism group, and unitary antipode on operator-algebraic
level. Still to be done: Insert the proof that the scaling group and unitary
antipode fit with Enocks theory.