letzte Aufräumarbeiten und Anpassen der Readme

README.md

src/main/java/edu/hsh/dbs2/imdb/entity/MovieMapper.java

src/main/java/edu/hsh/dbs2/imdb/logic/Manager.java

...java/edu/hsh/dbs2/imdb/util/EntityManagerFactoryUtil.java

src/main/java/edu/hsh/dbs2/imdb/util/Util.java

src/main/resources/META-INF/persistence.example.xml

src/test/java/edu/hsh/dbs2/imdb/TestDB.java