all: include-what-you-see fixes

After uint32_t fix from 1e82461875
it was good idea to check which headers where needed where. And
generally clean up the includes while doing the check.

src/analyze.c

@@ -33,7 +33,10 @@
  * official policies, either expressed or implied, of Sami Kerola.
  */
 
+/* #include <config.h> */
+
 #include <stddef.h>
+#include <stdint.h>
 #include <stdlib.h>
 
 #include "dhcpd-pools.h"