As a link clicker in a room on the standalone UI, I can send/receive text messages with the other room participant.

* No persistence of text messages after when the last person leaves the conversation (if A messages B, B leaves and then rejoins, the message is still there so long as A has stayed in the conversation)
* Messages can only be exchanged when in a room.
* In-room text message history available for the duration of the room

Acceptance criteria:
* When in a room alone:

**[P1]The chat edit box is disabled until someone else joins 

**[P1]If the room has contextual information, the contextual info appears in a speech bubble originating from the left


* When in a room with someone else:

**[P1]If the user has not used chat yet in this session, an indication "Type here..." appears in the chat edit box. This disappears once the user selects the chat area and won't appear again for the rest of the session once the user validates his first message sent

**[P1] If the room has contextual information, the contextual info appears in a speech bubble originating from the right for the link generator (a speech bubble originating from the left for the link clicker).

**[P1] New messages appear in speech bubbles with smooth transitions, older messages scroll up. The speech bubble originates from the right for the user's messages and from the left for messages from the link generator. A sound accompanies new messages received

**[P2] Every minute a timestamp is inserted next to a speech bubble. The timestamp only appears once per minute and any subsequent messages during that minute do not have a timestamp

**[P2] In the chat edit box a button allows inserting an emoticon
***Mousing over the button brings a tooltip
***Clicking the emoticon button opens a small pop up with a selection of Emoticons users can insert into their text
***Selecting an emoticon from the pop up adds the emoticon to the chat edit box

**[P2]Entering a URL manually renders the URL in a URL block (if this requires fetching the page title and favicon, a loader indicator gets displayed / If there is an error fetching the page information, then the URL is displayed in an empty URL block)

**[P3] Mousing over any URL block (includes the context block) will slightly change its color and make appear the Bookmark icon
*** Left clicking a URL block opens the URL in a new tab
*** Right clicking a URL block opens the contextual menu
*** Using the Bookmark icon will cause the URL to be added to the bookmarks

**[P3] A menu at the top of the chat window allows to:
*** Filter text out so that only URLs appear
*** Filter URLs out so that only text appears
*** Bookmark all URLs