[BSP] use RT_USING_LIBC instead of RT_USING_NEWLIB
[BSP] Update C++ compiling options
[BSP] Fix the gcc compiling issue in LPC408x bsp
[BSP] fix GCC compiling issue when enable C++ support
[C++] fix the ctors initialization issue
Merge pull request #361 from BernardXiong/master

Add cplusplus and sensor framework.
Merge branch 'master' of https://github.com/BernardXiong/rt-thread
Merge remote-tracking branch 'upstream/master'