Fixed WatchDir test making it less time dependent

Now use proper wait / notify logic. Test is probably less readable, but more robust. A failing test might take up to 5 seconds to fail (but we should not have failing tests, should we ?). The happy path is now as fast as possible.

Also fixed a buggy test on watching files (no idea why it was wrongly passing).
Merge pull request #168 from jmxtrans/update-maven-plugins-to-latest-versions

Fixed WatchDir test making it less time dependent
All indentation is now tab based.

As it seems that tab based indentation is the standard of the project, make sure that this is the case for all files. This will make future refactorings easier to review.

Note that checkstyle max allowed violations have been adapted to reflect the state of the project.
Merge pull request #169 from jmxtrans/space-removal

All indentation is now tab based.
Fixed all Findbugs warnings

Also added findbugs:check to the Maven build to ensure no violations are added now that everything is clean.

Added guava & findbugs-annotations to the Ant build to preserve compatibility. It seems that deb / rpm generation is only available through Ant at the moment, so let's keep this working until those packages are also generated by Maven.