minor things

- link to HTML version of inline help
- fix type in Test_C64()
- remove extra spaces at end of line

src/main.c

@@ -48,6 +48,9 @@
  *
  * This Doxygen documentation is browsable on
  * https://pulkomandy.tk/projects/GrafX2/doxygen/ (updated nightly).
+ *
+ * The inline help is also available here :
+ * http://pulkomandy.tk/GrafX2/
  */
 /// declare global variables in main.c
 #define GLOBAL_VARIABLES

src/miscfileformats.c

@@ -2255,7 +2255,7 @@ static const char *c64_format_names[] = {
  */
 void Test_C64(T_IO_Context * context, FILE * file)
 {
-  long file_size;
+  unsigned long file_size;
   word load_addr;
   byte header[14];