ui: tweaks & fixes

[bboyatwork]

As a Clutter user I need to feel the familiarity to Twitter in order to feel confident using it.

• [x] 'Clutter' headline clickable
• [x] Separate meow feed from message area
• [x] Move handle under profile picture
• [ ] Change background image / find higher-res

From @science-girl:

• [ ] background graphic of kittens should be fixed not
• [x] set handle should be a dialog box that pops up upon opening page
• [x] after setting handle, return to screen to send message

[zippy]