Property system

[joreg]

• device node has input: "Properties" of type Dictionary<string,object>. whenever that dictionary changes the devices is reopened using these settings
• a SetProperty node can be connected downstream of the device node. it has an input "Name" (string) and an input "Value" (object). it has an output "Success" to inform whether the current camera supports the given property
• a GetProperty node returns a properties value (object) by a given name (string)
• a GetPropertyInfos returns a Spread<PropertyInfo> of all properties supported by the current camera