include config.h in all sources

After we've been hit by Large File Support problems several times in
the past week (which only occur on 32 bit platforms, which I don't
have), this is yet another attempt to fix the issue.

src/archive/bz2_plugin.c

@@ -21,9 +21,9 @@
   * single bz2 archive handling (requires libbz2)
   */
 
+#include "config.h"
 #include "archive_api.h"
 #include "input_plugin.h"
-#include "config.h"
 
 #include <stdint.h>
 #include <stddef.h>

src/archive/iso_plugin.c

@@ -21,6 +21,7 @@
   * iso archive handling (requires cdio, and iso9660)
   */
 
+#include "config.h"
 #include "archive_api.h"
 #include "input_plugin.h"
 

src/archive/zip_plugin.c

@@ -21,6 +21,7 @@
   * zip archive handling (requires zziplib)
   */
 
+#include "config.h"
 #include "archive_api.h"
 #include "archive_api.h"
 #include "input_plugin.h"