Replacing C libraries with Rust equivalents - student project

We are a group of students at NCSU.
As part of a Mozilla student [project](https://github.com/servo/servo/wiki/Replace-C-libraries-student-project#evaluate-replacing-c-libraries-with-modern-rust-equivalents) we have replaced the use of [rust-freetype](https://github.com/servo/rust-freetype) and [rust-stb-image](https://github.com/servo/rust-stb-image)  libraries in servo with [freetype-rs](https://github.com/PistonDevelopers/freetype-rs) and [image](https://github.com/PistonDevelopers/image) respectively.

The changes are described in more detail at  http://wiki.expertiza.ncsu.edu/index.php/CSC/ECE_517_Fall_2014/final_M1455_yaaa

Note: There is a known bug in the image decoding function. This bug probably is in the new image library.
An issue will be raised in that repository to track it. A bug id will be updated here shortly.