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/isc/taskpool.c

@@ -17,12 +17,8 @@
 
 #include <config.h>
 
-#include <isc/assertions.h>
-#include <isc/boolean.h>
-#include <isc/error.h>
 #include <isc/mem.h>
 #include <isc/taskpool.h>
-#include <isc/result.h>
 #include <isc/util.h>
 
 /***