Update CONTRIBUTING.md
Build/CMake: CMake options cleanup after febb26d4b711762b1ee605705e7fa949b9871df1
Tools/Extractors: Updated vmap_extractor for 6.0.2
Core/Misc: Remove dead code

Remove a double check on result of same function, with the 2nd being always true.
Tools/Extractors: Build fixes for linux
Core/Misc: Remove unsafe not thread-safe localtime() calls

Replace not thread-safe localtime() calls with thread-safe localtime_r().
Core/Misc: fixed a scenario when character factionchange create unexpected results, also moved packet generating code into unique methods

(Packet structure not verificated to 6.0.2)
DB/Hotfixes: Added Creature & CreatureDifficulty
DB/Hotfixes: Added BroadcastText

* ToDo: delete the one in `world`
Core/NetworkIO: *Fixed basic auth packets
Fixed basic character packets
Nulled all opcodes
Thanks to @Shauren for pointing some derps out

Signed-off-by: Sovak <sovak007@gmail.com>
DB/Hotfixes: Fixed a problem from the parser
DB: Create hotfixes_database.sql file and update .travis.yml to import hotfixes

Note: hotfixes_database.sql will be empty until the next TDB release

And here's a friendly reminder that trinity now uses 4 DBs: characters, auth, world and hotfixes
DB: Move hotfixes_database.sql to the /dev folder (just like world)
Battle.net: Fixed JoinRequestV2 and JoinResponseV2 structures
Core/PacketIO: Updated packet headers to 6.0
Merge pull request #13361 from Sovak/602

Core/NetworkIO: *Fixed basic auth packets
SQL: Removex 6x from file names
DB/Hotfixes: Added GameObjects
Core/Entities: First part of required database changes for migrating guids to 128 bit - all fields storing lowguid must be extended to uint64
Core/AHBot: Filter out from AHBot items that can't be looted

(cherry picked from commit 361d285ba3d42f0b5ec60bbb646d500ef6940488)