Added Rust-Empty

This fixes symlink build in the Piston infrastructure.

* Does not affect the existing way of building
* Added more git filters
Merge pull request #95 from bvssvni/master

Added Rust-Empty
Adds map() to Array1, and provides implementations for Vectors,
Points, Matrices, and Quaternions.

Signed-off-by: Aaron Jacobs <atheriel@gmail.com>