renamed most source files

tecs/str_util.c

@@ -1,3 +1,5 @@
+#include <stdlib.h>
+#include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
@@ -5,7 +7,7 @@
 #include <assert.h>
 #include <string.h>
 #include <ctype.h>
-#include "errhdl.h"
+#include "err_handling.h"
 #include "str_util.h"
 
 char *str_splitx(char *str, char sep, char *list[], int *n) {