255 stickies

Fix #255, and more specifically the following issues:
- deprecated methods in notice model, stickies and notices views
- modal windows realized by Thickbox;
- loading gif for modal windows;
- ajax forms for creating new stickies (stickies/create.js.erb);
- auto-check checkboxes for locations in the advanced options (locationcheckboxes.js)

The following issues are NOT yet fixed:
- toggle animation for advanced_options_div
- enable JS in the modal window (right now all ".only_js" elements are not showing)

We are thinking about using bootstrap for the modal windows, which may make the situation easier to fix. But right now this is a working version for creating new stickies.