Linux support for MonoDevelop plugin

Hi there,

This pull request add Linux support for the MonoDevelop plugin with the latest revision of MonoDevelop. I don't have made big changes so all must be good.

This plugin work with the latest MonoDevelop version from git. It work well on Linux, you just have to compile it yourself if your package manager haven't it.

I also update ThirdParty repo because there are some deps needed by Linux (libfreetype, etc.)