Pull request #90: [java.lang.ClassCastException] When adding HTMLSignature to userConfiguration

- Fixed Errormsg
Pull request #90: [java.lang.ClassCastException] When adding HTMLSignature to userConfiguration

- added Junit Test as mentioned by @vboctor
- the testAddSupportedElementsToDictionary() shows another issue because
validation of Elements only allows Int, long, byte, boolean primitives
but casting a primitive to Object also makes it a wrapper
Pull request #90: [java.lang.ClassCastException] When adding HTMLSignature to userConfiguration

- JavaDoc clarified @vboctor
Pull request #90: [java.lang.ClassCastException] When adding HTMLSignature to userConfiguration

- moved assignment of UserConfigurationDictionaryObjectType.StringArray
in the StringArray block
- assignment of dictionaryObjectType, valueAsString now where it is
needed. Variables are also made final for single assignment.