Add support to LCTECH_STM32F103RBT6 Ebay boards

I made this code to make possible a initial support of Espruino over this LC-Tech board.
I test over my own board and it's work. (With somes TODO like Inverted LED over the board and BTN needs pullup to work..)

Another name of board: SainSmart STM32F103RBT6 ARM Cortex-M3 mini Development Board+Code
It's exactly this: http://www.amazon.com/SainSmart-STM32F103RBT6-Cortex-M3-Development-Board/dp/B005FXDXCE