[8364] Implement possibility reset client cache data from server side. Author: Fog

Implemented 2 way set cache data "version":
    * New db_version.cache_id field let set cache data version by DB content creators.
      This can be used for content releases by seting some unique value at each release.
      This value used by default.
    * New mangosd.conf config option let set (overwrite DB value) or use 0 for ignore.
      This can be used by serever admin for reset cache at some local changes.

    Note: values use at client login and then must be unique for long period time to avoid ignored
          at login some long not connected client with old same cache version value.

--HG--
branch : trunk

src/trinitycore/trinitycore.conf.dist

@@ -713,6 +713,11 @@ ChatLogTimestamp = 0
 #        Default: 0 - recheck offhand slot weapon only at zone update
 #                 1 - recheck offhand slot weapon at talent reset also
 #
+#
+#    ClientCacheVersion
+#        Client resets cache if WDB files' version is not equal to this value.
+#        Default: 0 (no real meaning)
+#
 #    Event.Announce
 #        Default: 0 (false)
 #                 1 (true)
@@ -777,6 +782,7 @@ MailDeliveryDelay = 3600
 SkillChance.Prospecting = 0
 SkillChance.Milling = 0
 OffhandCheckAtTalentsReset = 0
+ClientCacheVersion = 0
 Event.Announce = 0
 BeepAtStart = 1
 Motd = "Welcome to a Trinity Core server."