The new highlight logic follows a simpler model. It supports: * highlighting of whole words in a message * highlighting messages by sender name * highlighting if the user’s name is mentioned Possible actions for these highlights are text colouring, sound playback of WAV files, and system notifications. In addition the user can decide to receive sound and system notification on general incoming direct and group messages. Redesigned the highlight configuration UI dialog for this new model. ChatMessageParser class now deals with all parsing and marking up the chat message with the matching HighlightActions. Highlighter class has been extended to deal with all sound and system notification highlights that should be emitted by a specified chat message. Moved some tests over to gtest in the process. Test-Information: Tested UI on macOS 10.12.3 with Qt 5.7.1. Manually tested that correct system notification are emitted on mentions, keyword highlights and general messages. Added new unit tests to cover new highlighting behaviour. Change-Id: I1c89e29d81022174187fb44af0d384036ec51594