#175 added delete method in HibernateUtil.java
#175 added delete method for Algorithms
#175 added test for delete call on unstored Algorithms
#175 implemented delete on DatabaseConnection.java
#175 pulled store and delete methods to abstract class
store method is abstract
in algorithm retrieveAll uses criteria
#175 made DatabaseConnection.java extend ResultsDbEntity
removed duplicate tests in AlgorithmTest.java and DatabaseConnectionTest.java
#175 made Execution extend ResultsDbEntity
#175 made Inputs extend ResultsDbEntity
fixes #175 made Result extend ResultsDbEntity
added test for Algorithm constructor
added exception handler in DatabaseInitializer.java
Merge branch 'master' into results_db

Conflicts:
	backend/src/main/java/de/uni_potsdam/hpi/metanome/results_db/DatabaseConnection.java
	backend/src/main/java/de/uni_potsdam/hpi/metanome/results_db/FileInput.java
	backend/src/main/java/de/uni_potsdam/hpi/metanome/results_db/Input.java
	backend/src/main/java/de/uni_potsdam/hpi/metanome/results_db/TableInput.java
#177 #152 Add delete functionality to services.
#152 Implement delete functionality for algorithms in frontend.
#177 Implement delete functionality for inputs in frontend.
#177 Database Connection can only be deleted, if there is no foreign key relation.
When saving a new data source, the run configuration page gets updated.
Fixed bug in test.
Merge branch 'master' into results_db

Conflicts:
	frontend/src/main/java/de/uni_potsdam/hpi/metanome/frontend/client/datasources/DataSourcePage.java