Updated .gitignore. As we will be using ANT, we won't need any eclipse specific files. Used a template from https://github.com/github/gitignore/blob/master/Global/Eclipse.gitignore. Added some lines to that.
Removed eclipse-specific files. Resources folder now in standard location. Changed folder structure from /tree/homework_3 to /POS as we will be developing the same project throughout the course and we will be adding tags to states, which were required for homeworks. (Maybe the project's root should be the root of the github repository, not sure.)