Initialises SDL with the desired flags or default ones.
A full list of init flags and info on Initializing SDL can be found in the SDL Documentation.
The normal SDL_Init() can be used without problems but LEXSDL_SetupEvents() will need to be manually called since it is implicitly called with LEXSDL_Init().
LEXSDL_SetupEvents() could fail in a extreme case and the fixed error is -1;