Fixed compiler warnings

Fixed compile-pentium64 scripts
Fixed wrong estimate of update_with_key_prefix in sql-bench
Merge bk-internal.mysql.com:/home/bk/mysql-5.1 into mysql.com:/home/my/mysql-5.1
Fixed unsafe define of uint4korr()
Fixed that --extern works with mysql-test-run.pl
Small trivial cleanups
This also fixes a bug in counting number of rows that are updated when we have many simultanous queries
Move all connection handling and command exectuion main loop from sql_parse.cc to sql_connection.cc
Split handle_one_connection() into reusable sub functions.
Split create_new_thread() into reusable sub functions.
Added thread_scheduler; Preliminary interface code for future thread_handling code.

Use 'my_thread_id' for internal thread id's
Make thr_alarm_kill() to depend on thread_id instead of thread
Make thr_abort_locks_for_thread() depend on thread_id instead of thread
In store_globals(), set my_thread_var->id to be thd->thread_id.
Use my_thread_var->id as basis for my_thread_name()
The above changes makes the connection we have between THD and threads more soft.

Added a lot of DBUG_PRINT() and DBUG_ASSERT() functions
Fixed compiler warnings
Fixed core dumps when running with --debug
Removed setting of signal masks (was never used)
Made event code call pthread_exit() (portability fix)
Fixed that event code doesn't call DBUG_xxx functions before my_thread_init() is called.
Made handling of thread_id and thd->variables.pseudo_thread_id uniform.
Removed one common 'not freed memory' warning from mysqltest
Fixed a couple of usage of not initialized warnings (unlikely cases)
Suppress compiler warnings from bdb and (for the moment) warnings from ndb

sql/scheduler.cc

@@ -0,0 +1,88 @@
+/* Copyright (C) 2007 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/*
+  Implementation for the thread scheduler
+*/
+
+#ifdef USE_PRAGMA_INTERFACE
+#pragma implementation
+#endif
+
+#include <mysql_priv.h>
+
+/*
+  'Dummy' functions to be used when we don't need any handling for a scheduler
+  event
+ */
+
+static bool init_dummy(void) {return 0;}
+static void post_kill_dummy(THD* thd) {}  
+static void end_dummy(void) {}
+static bool end_thread_dummy(THD *thd, bool cache_thread) { return 0; }
+
+/*
+  Initialize default scheduler with dummy functions so that setup functions
+  only need to declare those that are relvant for their usage
+*/
+
+scheduler_functions::scheduler_functions()
+  :init(init_dummy),
+   init_new_connection_thread(init_new_connection_handler_thread),
+   add_connection(0),                           // Must be defined
+   post_kill_notification(post_kill_dummy),
+   end_thread(end_thread_dummy), end(end_dummy)
+{}
+
+
+/*
+  End connection, in case when we are using 'no-threads'
+*/
+
+static bool no_threads_end(THD *thd, bool put_in_cache)
+{
+  unlink_thd(thd);
+  pthread_mutex_unlock(&LOCK_thread_count);
+  return 1;                                     // Abort handle_one_connection
+}
+
+
+/*
+  Initailize scheduler for --thread-handling=no-threads
+*/
+
+void one_thread_scheduler(scheduler_functions* func)
+{
+  func->max_threads= 1;
+#ifndef EMBEDDED_LIBRARY
+  func->add_connection= handle_connection_in_main_thread;
+#endif
+  func->init_new_connection_thread= init_dummy;
+  func->end_thread= no_threads_end;
+}
+
+
+/*
+  Initialize scheduler for --thread-handling=one-thread-per-connection
+*/
+
+#ifndef EMBEDDED_LIBRARY
+void one_thread_per_connection_scheduler(scheduler_functions* func)
+{
+  func->max_threads= max_connections;
+  func->add_connection= create_thread_to_handle_connection;
+  func->end_thread= one_thread_per_connection_end;
+}
+#endif /* EMBEDDED_LIBRARY */