Add gitignore

We need this so that Git will report the top-level Servo repo as clean.
Ignore /compile
Merge pull request #1 from SimonSapin/ignore-compile

Ignore /compile
Cargoify fontconfig

This creates a dummy Rust crate that is just a carrier for a native
library. Packages like rust-fontconfig can then depend on this.
Merge pull request #3 from metajack/cargoify

Cargoify