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

mysys/my_error.c

@@ -120,7 +120,7 @@ int my_error(int nr,myf MyFlags, ...)
       ...	variable list
 */
 
-int my_printf_error (uint error, const char *format, myf MyFlags, ...)
+int my_printf_error(uint error, const char *format, myf MyFlags, ...)
 {
   va_list args;
   char ebuff[ERRMSGSIZE+20];