Added Debug, Display, and Default to Vectors and Quaternions.

This also adds an example for Vectors and Quaternions.

examples/quaternion.rs

@@ -0,0 +1,14 @@
+extern crate sigils;
+
+
+
+use sigils::quaternion::{Quaternion};
+
+
+pub fn main()
+{
+   let quat: Quaternion<f64>;
+
+   quat = Quaternion::<f64>::default();
+   println!("Quaternion: {}", quat);
+}