* Drop EventManager from GameDef & do some client cleanups
* EventManager is only used by Client. Don't expose it on Server & GameDef for nothing
* Drop Client::event() in favor of direct calls to getEventManager
* Cleanup some event put from new + put to put(new)
* MtEvent: add Type(u8) enum
* This will enhance event performance & ensure stricter type
* Drop MtEvent::checkIs (unused)
* clang-tidy reported fixes
* Code style
* Move event_manager.h to the client directory as it's only used by client
Add EventManager unittests + switch to unordered_map as order is not important here
Drop a unused function
* Modernize source code: last par
* Use empty when needed
* Use emplace_back instead of push_back when needed
* For range-based loops
* Initializers fixes
* constructors, destructors default
* c++ C stl includes
* C++11 patchset 9: move hardcoded init parameters to class definitions
C++11 introduced the possibility to define the default values directly in class definitions, do it on current code
Also remove some unused attributes
* CollisionInfo::bouncy
* collisionMoveResult::collides_xy
* collisionMoveResult::standing_on_unloaded
* Clouds::speed
* More constructor cleanups + some variables removal
* remove only write guiFormSpecMenu::m_old_tooltip
* move header included inside defintions in genericobject.h
* remove some unused since years exception classes
* remove unused & empty debug_stacks_init
* remove unused & empty content_nodemeta_serialize_legacy
* remove forgotten useless bool (bouncy) in collision.cpp code
