#230 Sb_stadtbildUtils.setModelForComboBoxesAndDecorateIt() check if metaclass is not null
#230 surround Sb_StadtbildWindowSearch constructor with try-catch and create the models for some components only if the user has permissions
#230 BillingWindowSearch: create some models only if the user has the permessions
Merge branch 'bug/230-metaclass-not-found-stadtbildersearch' into dev