Add DBM Phase triggers

- Callback can be used by external addons like Weakauras in its triggers.
- Fire stage callback on variable recovery
- Added public facing stage api, that allows for mods or Weakauras request current stage a mod is in (if applicable) for either specific mod by mod id OR by simply doing request without modId, and having DBM just give a return for first mod in combat table
- Boss modules migrated to use newly added SetStage function

Custom DBM commits with appropriate ReleaseRevision bump to 7005 to ensure DBM is compatible:

https://github.com/Zidras/DBM-Icecrown/commit/ff3a3a27502c73ed5686029bcca3be3afd8a459f

https://github.com/Barsoomx/DBM-wowcircle/commit/6388338048ad1916f2753995f02057889d3fc20b

WeakAuras/GenericTrigger.lua

@@ -2453,6 +2453,7 @@ do
   local bars = {}
   local nextExpire -- time of next expiring timer
   local recheckTimer -- handle of timer
+  local currentStage = 0
 
   local function dbmRecheckTimers()
     local now = GetTime()
@@ -2542,6 +2543,10 @@ do
         end
       end
       WeakAuras.ScanEvents("DBM_TimerUpdate", id)
+    elseif event == "DBM_SetStage" then
+      local mod, modId, stage = ...
+      currentStage = stage
+      WeakAuras.ScanEvents("DBM_SetStage", ...)
     else -- DBM_Announce
       WeakAuras.ScanEvents(event, ...)
     end
@@ -2583,6 +2588,10 @@ do
     return true
   end
 
+  function WeakAuras.GetDBMStage()
+    return currentStage
+  end
+
   function WeakAuras.GetDBMTimerById(id)
     return bars[id]
   end