more infomation:
http://www.rt-thread.org/phpBB3/topic2965.html

fix #211

empty is confused in dfs_filesystem_lookup.

More tc

The tc thread should delay more time than tid2 in order to let it run
the test. The hard-coded "27" is not enough in some cases.

TCs are supposed to exit with the TC_STAT_RUNNING cleared. If it forgot
to do this, do it by ourselves.

dfs: refine code

clean code with pointer rather than index

Fix tc

decrease indentation to make cleaner code
fix mkfs bug when there is no mkfs implementation

The sem that has been created should be deleted. The sem that has been
inited should be detached.

There can be a race condition that the sem has alread been detached
after we did the cleanup. Besides, there is a RT_IPC_CMD_RESET command
in rt_sem_control which is more clear in setting the sem values.

update bsp/simulator

clean code in SConstruct and application.c, disable RTGUI in rtconfig.h
by default.

Sqlite

fixed _sys_read()/_sys_write() issues.