--==-- AutoFocusCast Functionality Description --==--

This addon allows the default UI's action buttons to automatically retarget abilities which cannot be
used on the target to the focus instead. For instance, when trying to cast a heal with an enemy
targeted, the spell will go to the focus instead. Likewise, when trying to use a damage ability with
a friend targeted, the ability will go to the focus. If no focus exists, or the focus isn't the proper
affiliation for retargeting (not an enemy for harmful abilities, or not a friend for helpful abilities),
normal behaviour (auto-self-cast if enabled, or a targeting cursor if not) will take place. If auto-
self-cast is enabled and no target exists, the spell will ignore the focus. Basically, the addon will
only retarget spells when you have a target and that target is inapplicable for the spell.

Due to the nature of the UI's architecture, this is a per-button override, and can't be done globally
for all buttons. It is written specifically for the default UI buttons, and will work only with plain actions,
not macros.