Added faction:icon tag

Reference: #2

ElvUI_CustomTags/core.lua

@@ -15,6 +15,7 @@ local GetNumGroupMembers = GetNumGroupMembers
 local IsInGroup = IsInGroup
 local IsInRaid = IsInRaid
 local UnitClass = UnitClass
+local UnitFactionGroup = UnitFactionGroup
 local UnitHealth = UnitHealth
 local UnitHealthMax = UnitHealthMax
 local UnitIsDead = UnitIsDead
@@ -591,6 +592,20 @@ ElvUF.Tags.Methods['name:long:abbreviate'] = function(unit)
 	return name
 end
 
+ElvUF.Tags.Events['faction:icon'] = 'UNIT_NAME_UPDATE'
+ElvUF.Tags.Methods['faction:icon'] = function(unit)
+	local faction = UnitFactionGroup(unit)
+	local str = ""
+	
+	if faction == "Alliance" then
+		str = "|TInterface\\AddOns\\ElvUI_CustomTags\\media\\Alliance:0:0:0:-1|t"
+	elseif faction == "Horde" then
+		str = "|TInterface\\AddOns\\ElvUI_CustomTags\\media\\Horde:0:0:0:-1|t"
+	end
+	
+	return str
+end
+
 ElvUF.Tags.Methods["classcolor:player"] = function()
 	local _, unitClass = UnitClass("player")
 	local String