Updated Polish translation
Updated Spanish translation
check_property_type() should return true if we don't know what the type
should be.
No need to contruct a PropertyValue
Add an EmptyValue to the PropertyValue variant.

Add helper function for the type.

The fixes an assert when setting a property that didn't exists before
as we check the types.

Passing an EmptyValue delete the property.
Added a test for the ConfigDataBinder
Make sure the ConfigDataBinder is initialised properly

Better catch exception when using config data. Exception raise
caused but improperly initialised data.
Persist the expanded states of the workspace treeview.

Add a librarylocal configuration.