see changelog below

[kaytrance]

• upon first page load all chat history now gathered by single event
• user can type @ and some letter - a popup with matched users will pop up
• user can click on matched nickname to add mention to chat, or use up/down arrows to change user in matched list and hit enter to add mention to chat
• upon new message arrival in chat if user was mentioned, a notification sound will be played
• added error message if new user upon registration has a nickname with invalid characters