[all] Setup dev environment
[gpio] Added detect events and functions

Added detect events for high/low and asynchronous rising/falling

Added the wrapper SetGpioDirection and a function to read pins.
[README] Markdown fix, made code behave like code
[GPIO] Removed empty lines and added TODO line for PUD function
[README] Markdown fix, made code behave like code
Merge pull request #3 from Snigelson/master

Latest changes from Snigelson