Updated JUnit to version 4.11

New tests will make use of JUnit's assumeThat method which uses
hamcrest. JUnit 4.11 provides a cleaner integration of hamcrest than
4.8.2
Added test for handling of file encodings in FileOpener
Merge branch 'master' of
https://github.com/culturegraph/metafacture-core.git

Conflicts:
	pom.xml