[z2439] Don't do periodic heal ticks if the target is already at max health.

If a target is at maximum health already periodic healing spells should
not tick.

From the healer's point of view this means far less overhealing, improving
their healing performance information.

Fixes cmangos/issues#385.
[z2440] Hide known recipes when the Usable box is checked in the AH.

Fixes cmangos/issues#394.