Adapting #1145 for merging

client/methods/saveRoomName.coffee

packages/rocketchat-lib/server/functions/setUsername.coffee

packages/rocketchat-lib/server/methods/setUsername.coffee

packages/rocketchat-lib/server/startup/settings.coffee

packages/rocketchat-mentions/client.coffee

packages/rocketchat-mentions/server.coffee

server/lib/accounts.coffee

server/methods/createChannel.coffee

server/methods/createPrivateGroup.coffee

server/methods/getUsernameSuggestion.coffee

server/methods/saveRoomName.coffee

server/publications/channelAutocomplete.coffee

server/restapi/restapi.coffee