MIAMI — Midway through the third quarter of the Miami Heat’s 118-85 victory over Orlando on Sunday, second-year center Dexter Pittman got right in Dwight Howard’s face as though he wanted to start something. The result of the altercation was a double foul — one on Pittman, one on Howard — and a measure of respect. But it didn’t answer any questions about the Heat’s toughness in the middle. Miami’s four-headed center — starter Joel Anthony, Pittman, and power forwards Chris Bosh