CLEANUP: include: tree-wide alphabetical sort of include files

This patch fixes all the leftovers from the include cleanup campaign. There
were not that many (~400 entries in ~150 files) but it was definitely worth
doing it as it revealed a few duplicates.
diff --git a/src/mailers.c b/src/mailers.c
index 94ed5b4..76d6a69 100644
--- a/src/mailers.c
+++ b/src/mailers.c
@@ -20,13 +20,13 @@
 #include <haproxy/list.h>
 #include <haproxy/mailers.h>
 #include <haproxy/pool.h>
-#include <haproxy/tools.h>
-#include <haproxy/time.h>
-#include <haproxy/thread.h>
 #include <haproxy/proxy-t.h>
 #include <haproxy/server-t.h>
 #include <haproxy/task.h>
 #include <haproxy/tcpcheck.h>
+#include <haproxy/thread.h>
+#include <haproxy/time.h>
+#include <haproxy/tools.h>
 
 
 struct mailers *mailers = NULL;