Inverted alpha settings for custom counters watching spell charges

For charges, being full is the default state, so we need to treat full the same as health or mana being full. (ticket #231)
Also fixed the "target" variable never getting set on custom counters or custom counter bars because they were overriding the PLAYER_TARGET_CHANGED event that the base class was registering.
Also also fixed numeric display mode for custom counters not using the correct gradient scaling when the number hit 0. It was using the same scaling as graphical mode where 0 displays nothing and needs to be accounted for separately.

modules/CustomCount.lua

@@ -296,6 +296,11 @@ function IceCustomCount.prototype:Enable(core)
 	self:UpdateCustomCount()
 end
 
+function IceCustomCount.prototype:TargetChanged()
+	IceCustomCount.super.prototype.TargetChanged(self)
+	self:UpdateCustomCount()
+end
+
 
 
 -- 'Protected' methods --------------------------------------------------------
@@ -421,6 +426,9 @@ function IceCustomCount.prototype:GetGradientColor(curr)
 	local r, g, b = self:GetCustomColor()
 	local mr, mg, mb = self:GetCustomMinColor()
 	local scale = max > 1 and ((curr-1)/(max-1)) or 1
+	if self.moduleSettings.countMode == "Numeric" then
+		scale = max > 1 and (curr/max) or 1
+	end
 
 	r = r * scale + mr * (1-scale)
 	g = g * scale + mg * (1-scale)
@@ -435,7 +443,7 @@ function IceCustomCount.prototype:UpdateCustomCount()
 		return
 	end
 
-	local points = IceStackCounter_GetCount(self)
+	local points = IceStackCounter_GetCount(self) or 0
 	local max = IceStackCounter_GetMaxCount(self)
 
 	if max > #self.frame.graphical then