WowAce

Shadowed:
    - Fixed bug in the activeHot tracker (thanks Adirelle)
    - Fixed removeAllRecord calls triggering errors
    - Fixed a stack overflow if "spell" is nil in the averages metatable
    - Added new event HealComm_GUIDDisappeared(event, guid) fires when a GUID goes "missing" either because they have an active hot and are outside visible range, they are a pet that was dismissed with hots on them or they left a group with heals on them
    - Went back and clarified/cleaned up some comments that were old or out of date
    - Fixed an error when PARTY_MEMBERS_CHANGED fired for players who were not a healer class
    - Fixed guidToUnit/guidToGroup being removed before parseHealEnd when sanity checking
    - Fixed index nil table error when a group is disbanded while zoning
    - Fixed GetCasterHealAmount() now returns nil if no healing is incoming
    - Fixed getRcord typo on line #1904