New debug scheme with explicit debug channels declaration.

diff --git a/files/dos_fs.c b/files/dos_fs.c
index 330ac4d..3e5a281 100644
--- a/files/dos_fs.c
+++ b/files/dos_fs.c
@@ -33,6 +33,9 @@
 #include "options.h"
 #include "debug.h"
 
+DECLARE_DEBUG_CHANNEL(dosfs)
+DECLARE_DEBUG_CHANNEL(file)
+
 /* Define the VFAT ioctl to get both short and long file names */
 /* FIXME: is it possible to get this to work on other systems? */
 #ifdef linux