Refactor String path -> Path path

[Mession]

Instead of strings for paths, we should prefer java.nio.file.Path.

[nimirum]

I can try to do this

[jamo]

You probably should be aware of the work done here: testmycode/tmc-core#70 even though this work shouldn't collide.

[ljleppan]

NB: Prefer usage of java.nio instead of java.io.

That is, use Files.exists(Path path)* instead of path.toFile().exists() etc. and preferably replace any existing usage of the class File with Path.

*) http://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html.