Maven integration with tutorial samples and upgrade to libgdx 0.9.9

Hi Mete,

I'm starting to study LibGDX and found your MTX project which looks very promising. I decided to contribute a couple of features to it, namely:
1) Integration with Maven using official libgdx maven archetype - https://github.com/libgdx/libgdx-maven-archetype
2) Maven project sources updated to libgdx 0.9.9 version.
3) Tutorial samples included into maven project.

I assume it can be useful as it allows developer to be IDE-agnostic and stick to latest libgdx versions automatically if desired.

Feel free to ask questions and push changes if you find them useful.

Regards and Happy New Year,
Vladimir