Updated checkstyle configuration

Added SuppressionCommentFilter and SuppressWithNearbyCommentFilter to
allow suppression of checkstyle warnings.
Added test case for ObjectFileWriter
Merge branch 'master' of https://github.com/culturegraph/metafacture-core.git
Merge branch 'master' of https://github.com/culturegraph/metafacture-core.git
Fixed typos and improved code layout (the things that really matter)
Added support for encodings to ObjectFileWriter and set default encoding
to UTF-8.