Added ADC library, as well as the beginning of the SRAM library. Currently, I'm doing to PIO pin dance and trying to fit everything in there... Which sucks. Likely, the LCD driver (sf240320) is going to just have to do a few extra instructions to get its data bus set. Too bad. Also, looks like the Due doesn't have A18 (for SRAM) available, meaning likely we won't get all 4Mb of the SRAM chip. Fucking USB OTG...