Merge upstream changes: Merge FILEIO changes

FILEIO has been updated to resolve relative paths inside FILEIO::Fopen(),
which has been already done in System3-sdl2.

FILEIO::Fgets() now uses a length param.

Callsites for these functions are also updated to reduce the diff from
upstream.

src/sys/nact_crc32.cpp

@@ -77,6 +77,7 @@ uint32 NACT::calc_crc32(const char* game_id)
 
 	uint32 crc = 0;
 	FILEIO* fio = new FILEIO();
+
 	if(fio->Fopen("ADISK.DAT", FILEIO_READ_BINARY)) {
 		uint32 table[256];
 		for(int i = 0; i < 256; i++) {