Core/Items: Fix logic in Player::AddItem

Should send client the amount it gave you, not the amount it couldn't
give you
declared WEATHER_STATE_FOG
Core/Auras: Restore part of 1845ab79 that was accidentally reverted
Update src/server/game/Weather/Weather.cpp
Merge pull request #9234 from ak47sigh/patch-1

declared WEATHER_STATE_FOG
Merge pull request #9220 from roc13x/master

Core/Items: Fix logic in Player::AddItem
Buildsystem: Disable building the nonfunctional meshextractor.tool (not in a production-state atm), it CAN however be built with with using the -DWITH_MESHEXTRACTOR flag (not documented as option, and will most probably change in the future)
SQLs: Rename some old SQL files to match standards
Core/Vehicles: Refactor some parts of vehicle system

- Fix a few crashes:
Closes #9235
- Simplify and get rid of lots of redundant and silly code
- Optimisations in Unit::ChangeSeat
- More documentation
Core: Whitespace cleanup
Core/Vehicles: Prevent infinite loop in VehicleJoinEvent:Abort
Merge branch 'master' of git://github.com/TrinityCore/TrinityCore into teste2