Make otclient's framework flexible enough to run console apps like
servers, so this mean is possible to build otclient versions without
graphical interface and use it's framework to code servers
* Split game module into game and game_interface
* Move core_lib to corelib
* Move miniwindow to corelib
* Introduce init.lua script for initializing the client, giving much more flexibility
* OTClient is no longer Application derived and is much simpler
* Fix recursive reference memory leak in UIWidget
* Make Event/ScheduledEvent memory-leak safe
* Fix exit crashs by freeing graphics resources before destroying GL context
* Add many asserts to avoid any leak regression
* Add cotire cmake module to speedup compilation https://github.com/sakra/cotire
* Fix clang error and warnings
* Rename Font to BitmapFont to fix conflict with Xlib.g Font typedef
* Remove legacy PCH support
* Improve Position hash