[USB]fix rt_usbd_set_config() BUG which set the USB device to configuration state before enumerating the device.
Merge pull request #258 from aozima/pulls

update MSH ifconfig and add MSH netstat.
scons: seperate the BSP build with the kernel build

BSPs could have their own components/ etc. If they point to the same
folder, SCons would find the wrong source code to compile.
scons: no need to set RTT_ROOT as Repository

In SCons manual:

=================
In order to inform the C compiler about the repositories,  SCons will
add appropriate -I flags to the compilation commands for each directory
in the $CPPPATH list. So if we add the current directory to the
construction environment $CPPPATH like so:

    env = Environment(CPPPATH = ['.'])
    env.Program('hello.c')
    Repository('/usr/repository1')

Then re-executing SCons yields:

    % scons -Q
    cc -o hello.o -c -I. -I/usr/repository1 hello.c
    cc -o hello hello.o
=================

The additional include directory is definitely not what we want. Just
remove the additional Repository line.
Merge pull request #254 from weety/Branch_usb

[USB]fix rt_usbd_set_config() BUG which set the USB device to configurat...
logtrace: add const modifier to the APIs

Compiler may do more optimization when the parameter is const.
logtrace: add log_session_lvl

log_session_lvl is suitable for performance critical places where in
most cases, the log is turned off by level. If the session is const and
the level is greater than session->lvl, the whole function will be
optimized out.
Merge pull request #260 from grissiom/logtrace-next

Logtrace next
Merge pull request #259 from grissiom/fix-scons

Fix scons
examples/kernel: fix warnings issued by Clang

Fix some "unused variable" and "used before set" warnings.
dfs: assert the path is not null in dfs_filesystem_lookup

Clang complains about "Null pointer argument in call to string
comparison function". So assert on it.
pthreads: remove some useless variables
finsh: add check on converting octal numbers

The digit in octal numbers should with in 0~7. Check on it in
token_proc_number. This issue is found by Clang.
msh: remove usless ptr set

The ptr is set in the following code. So remove the first one.
minilibc: no double braces in if statement
Merge pull request #262 from grissiom/misc-fix

Misc fix
[bsp/taihu] fix the link error

The taihu.lds hardcoded the path of start_gcc.o. Change it as the layout
of build/ has change by commit a03816ef9aa583bb.
Merge pull request #263 from grissiom/fix-taihu

[bsp/taihu] fix the link error
[mempool] reset the thread->error before suspending thread

Time out result and other errors is recorded in thread->error. Dirty
error will screw up the error handling code after the thread has been
wake up.
Merge pull request #266 from grissiom/fix-mempool

[mempool] reset the thread->error before suspending thread