Add support for SSD1306 controller and STM32L1xx device.

Added support for SSD1306 controller by Solomon Systech. Similar if not the same as the SSD1303 controller.  Added support for the STM32L1xx microcontroller family. Code tested and functional on STM32L-DISCOVERY development board. Added implementation to utilize SPI transfer via DMA instead of page by page transfer. Since this transfers the entire buffer it defeats the purpose of the bounding box. Need to add supporting configuration code to setup DMA.

Commented out some mulitiple definitions of the frame_buffer in glcd.h. My IDE removed some trailing white space in some files.

Updated README for new controller and device.

New Symbols:
GLCD_DEVICE_STM32L1XX
GLCD_CONTROLLER_SSD1306
GLCD_CONTROLLER_SSD1306_DMA