Add logback conf for category integration tests.
Add toString for some TypeReferences.
Implement HttpRequest.toString
Implement DeleteCategoryCommand.toString
Use Iterable instead of list in IsInPredicate.
Test IsInPredicate.
Prepare escaping of Strings in queries.
The base Exception class of sphere related errors can be filled with project and request related data.
Update dokumentation.
Add String escaping for queries.