Perspective Transform, Unit Tests and Numeric.js!

I made a bunch of changes to the library AffineTransform code. It's a lot shorter now, and using numeric.js, it is a lot faster than before. Also, I implemented the 4 point version of the transform for arbitrary distortions. The image below (from google) explains the different types of transforms.

![transformation](https://f.cloud.github.com/assets/313194/813991/414f0ba6-ef0d-11e2-8ecf-c3afee636598.png)

I also added unit tests with mocha, and a package.json file.

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### Remaining TODO
- Improve test cases (nowhere near thorough enough)
- Update readme
- Rename project to Projective?
- Benchmark testing
- Minify JS