Corrected README.md
Merge pull request #1 from tkellogg/patch-1

Corrected README.md
Adding .gitignore
Got it building for Rust v0.10
Merge pull request #3 from tkellogg/v0.10

Got it building for Rust v0.10
Made safe versions of arduino functions

This is just a thin wrapper around the extern functions so we can write fully safe Rust code. After all, what's the point
of writing Rust on Arduino without the full safety of Rust?
Created program to run demo circuit
Safer versions of digitalWrite & digitalRead