Add missing prototypes and includes

src/sdmhash.c

@@ -1,3 +1,5 @@
+#include "ucore/hash.h"
+
 unsigned long
 uc_sdbmhash(const unsigned char  *str)
 {

src/strlcpy.c

@@ -1,4 +1,5 @@
 #include <string.h>
+#include "ucore/string.h"
 
 size_t uc_strlcpy(char *restrict dst, const char *restrict src, size_t max)
 {

src/supervisor.c

@@ -8,6 +8,7 @@
 #include <errno.h>
 #include <string.h>
 #include <limits.h>
+#include "ucore/supervisor.h"
 
 
 #define CLEAN_EXIT 11