New debug scheme with explicit debug channels declaration.

diff --git a/files/file.c b/files/file.c
index f9851dd..91b8da8 100644
--- a/files/file.c
+++ b/files/file.c
@@ -46,6 +46,8 @@
 #include "server/request.h"
 #include "server.h"
 
+DEFAULT_DEBUG_CHANNEL(file)
+
 #if defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
 #define MAP_ANON MAP_ANONYMOUS
 #endif