Fix bad character in description
Break sequence detection working

- use correct TIMx prescaler to measure directly in us
- set only start_flag in CC interrupt
- use standard startup script for discovery kit
- alternate function inputs must use GPIO_Mode_IN_xxx
- interrupts must be enabled in NVIC
Working DMX512 receiver

- use PWM outputs on onboard LEDs on discovery kit
- all PWM outputs on custom hw
- update outputs in mainloop
- link StdPeriphLib sources in eclipse project

It is needed to read both data register and status register in UART interrut, it causes problems otherway.
Important flag variables should be volatile.