Fixes and sync with Classic DB

This pull request fixes a few errors (Rothide Gnolls, Naxxramas Acolyte, Plague Beast) and features a few additions of missing scripts in Classic (either not backtported from WotLK or missing in all branches).
Some of these fixes are probably applicable to TBC and maybe WotLK branches.
Tell me if you want to backport them by yourself or rather prefer that I open specific pull request for each branch.