Fixes and code cleanups after merge with 4.0.3

Warning handling and initial prepared statement handling (last not complete yet)
Changed a lot of functions that returned 0/1 to my_bool type.
GRANT handling now uses read/write locks instead of mutex
Change basic net functions to use THD instead of NET
(needed for 4.1 protocol)
Use my_sprintf instead of sprintf() + strlen()
Added alloc_query() to be able to chare query initialization code with
prepared statements.
Cleanup handling of SHOW COUNT(*) WARNINGS and SELECT LAST_INSERT_ID()

Note that the following test fails (will be fixed ASAP):
sub_select, union, rpl_rotate_logs and rpl_mystery22

libmysql/manager.c

@@ -138,7 +138,7 @@ MYSQL_MANAGER*  STDCALL mysql_manager_connect(MYSQL_MANAGER* con,
   }
   sock_addr.sin_port = (ushort) htons((ushort) port);
   if (my_connect(sock,(struct sockaddr *) &sock_addr, sizeof(sock_addr),
-		 0) <0)
+		 0))
   {
     con->last_errno=errno;
     sprintf(con->last_error ,"Could not connect to %-.64s", host);