Fix chms/jdotxt#15 and add unit tests

 - Add support for non-ASCII projects and contexts
 - Make unit testing a part of project build
 - Add unit tests for project and context parsing
Merge pull request #16 from mkalkov/master

Thank you! I am happy to see that you identified a problem and even fixed it immediately! I can now close chms/jdotxt#15 and unit testing seems like a great idea. Thanks also for the build.xml cleanup ;)

As all of the code (apart from minor modifications) that handles the todo.txt files and datastructures came from the original Android app, I highly recommend that you also try to get your modifications into https://github.com/ginatrapani/todo.txt-android