Chat-filter for Commo Rose messages

Added a better differentiation in the chat tab for messages generated by the Commo Rose (now displaying in dark violet and with the "[Commo Rose]" prefix), also adapted the localization for the different messages a bit.

To further extend this feature, another checkbox was introduced, allowing the admin to switch off Commo Rose messages completely (messages hidden by default). This checkbox gets disabled and hidden when not connected to a Battlefield 4 server.