DB/Update: Return To...RP event update

By @Foldor fixes #10886
Tools/MeshExtractor: Fixed mmap extracting for instance maps and fixed a number of issues.
ToDo:
Cleanup the code a bit.
WILL NOT CURRENTLY WORK WITH TrinityCore, if you want to test it, use the --extract 32 flag of MeshExtractor.
Tools/MeshExtractor: Some more cleanup.
Tools/MeshExtractor: Forgot to push some changes.