Partially revert a36a0a77ef.

Cleaning databases for old/deprecated and expired quests should never be a
developers choice specifically. This should be done by admins, not developers,
through the use of the already existing paramters found in the worldserver config :
CleanCharacterDB / PersistentCharacterCleanFlags

An adjustment to the respective questloader prepared statement has been done to
accomodate for the earlier change (by not loading such quests into memory at all).

Documentation for how this cleanup-procedures work already exists in the core :
doc/CharacterDBCleanup.txt.

sql/updates/characters/2012_03_01_00_characters_character_queststatus.sql

@@ -1 +0,0 @@
-DELETE FROM `character_queststatus` WHERE `status`=0;