First attempt to compile for linux. Had to fix some errors and warnings but it does compile on linux, though it has not been tested yet. Changed includes from SDL.h to SDL/SDL.h, will need to alter the include structure on windows for this to work. Changed ERR to ERROR to prevent an error with ncurses. Changed numToString template function into 4 non-template functions: boolToString, intToString, floatToString, and doubleToString.