Advanced Swap Focus/Target Macro

Description:
Sets the focus if you don't have one; clears the focus if you're out of combat and don't have a target; targets the focus if you're in combat and don't have a target; otherwise swaps the target and focus.
Macro:

/focus [target=focus, noexists]
/target [combat, noexists] focus
/clearfocus [nocombat, noexists]
/stopmacro [target=focus, noexists]
/target focus
/targetlasttarget
/focus [exists]
/targetlasttarget