[Drivers] re-write serial framework.
[Build] Fix LPC4300 building.
[Drivers] re-write serial framework.
Merge pull request #302 from BernardXiong/master

[Drivers] re-write serial framework.
[BSP] remove rt_device_init_all() invoking.
[BSP] remove COMPONENTS_INIT for lpc176x and stm32f107 porting.
[BSP] remove rt_device_init_all() invoking.
[POSIX] fix mq_open and sem_open argument issue.
Merge branch 'master' of https://github.com/RT-Thread/rt-thread