Retrieves the dunning deadlines from the settings
Added getImage() to ResourceLoader.
Use ResourceLoader.getImage() in PDFHandler to load humboldt logo
correctly.
Use ResourceLoader.getStream() in CSVHandler to load properties file
correctly.
Deleted unnecessary resources.
Deleted unnecessary ressources (themes/mytheme).
Merge pull request #718 from B3nRa/UseResourceLoader#683#684_secondTry

Use resource loader#683#684 second try
Commented and simplified DunningViewModel
bind ViewModelComposer as Singleton
added basic JUnit test
Added dunning deadline settings to sql insert
Added pdf/Logo_Humboldt.png resource to src/main/resources.
Methoden für INSERT, UPDATE, DELETE von Collections hinzugefügt.

Automatisches feuern von UpdateEvents ausgestellt.
Merge pull request #723 from B3nRa/UseResourceLoader#683#684_secondTry

Added pdf/Logo_Humboldt.png resource to src/main/resources.
Added dunning settings to DunningViewModelTest
Changed key of dunning deadline settings
Removed default buttons
Dunning deadlines are added to property settings
Removed unneccessary comments
Merge pull request #725 from jidel/issue#715-primary_buttons

Removed default buttons