Allow LED to blink
Add gitignore
Merge remote-tracking branch 'zxc2694/master'

Conflicts:
	main.c
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'zxc2694/master'

Conflicts:
	main.c
Enable to use CM4F version FreeRTOS
Change CPU_CLOCK_HZ and TICK_RATE_HZ

CPU_CLOCK_HZ: Because STM32F4Discovery CPU Clock is 168MHz
TICK_RATE_HZ: This parameter usually is 1000. And It will
cause vTaskDelay()'s delay unit to be ms.
Merge pull request #1 from fboris/master

Enable CM4F