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/pthreads/thread.c

@@ -17,11 +17,7 @@
 
 #include <config.h>
 
-#include <errno.h>
-
-#include <isc/assertions.h>
 #include <isc/thread.h>
-#include <isc/error.h>
 
 #ifndef THREAD_MINSTACKSIZE
 #define THREAD_MINSTACKSIZE		(64 * 1024)