Server reorganization:
- moved request handlers to the specific C files
- moved handle management to handle.c
- moved server private includes to server/ instead of include/server/

diff --git a/server/select.c b/server/select.c
index 4121eac..013ba71 100644
--- a/server/select.c
+++ b/server/select.c
@@ -15,7 +15,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include "server/object.h"
+#include "object.h"
 
 /* select user fd */
 struct user