Megacommit of dozens of files.

Cleanup of redundant/useless header file inclusion.

ISC style lint, primarily for function declarations and standalone
comments -- ie, those that appear on a line without any code, which
should be written as follows:
   /*
    * This is a comment.
    */

lib/dns/gen-unix.h

@@ -30,8 +30,9 @@
 #ifndef DNS_GEN_UNIX_H
 #define DNS_GEN_UNIX_H 1
 
+#include <sys/types.h>
+
 #include <dirent.h>
-#include <unistd.h>
 
 #include <isc/boolean.h>
 #include <isc/lang.h>