Correctly fix buffer overflow in FS_ReturnPath by making zpath 256 as it is in MP.
Use FS_PathCmp in SP for pak sorting.
Use correct Sys_ListFiles for getmodlist in SP.
Cleanup getfilelist in SP that is used by gamecode
use BASEGAME define in MP FS_GetModList
Use correct size parameter in FS pak qsort (for 64 bit compat, MP)