Create a wrapper for grat window and append it to document body
Create overlay and placeholder for image

When every question is answered correctly, show congrat image with overlay behind it. Styling is done via CSS.

And when clicking the overlay, remove it
Remove congrat image (or, the placeholder atm) too when overlay is clicked
Update styles.css
Multiple changes, see longer description

- Reset all correct -greeting to default alert
- Disable self-made log console
- Add functionality to make double-starred text bold (i.e. **bold**)
- Add global flag to one of replace-calls in normalizeSpace
Merge pull request #3 from mkoske/development

Some modifications and a new feature to application (app.js)