Fix story styles: no negative margins, just .story-left and .story-right

min-width of page actually was 800 + 160*2 = 1120px, because 800px was
centered, and to see 160px on one side you needed to make the same
160px-space on the other side.
Now it is just 800, because 160px are inside .story (so .text is 640px wide).
Remove handlebars

This templating library is useless because fetching templates from js
is not allowed.
Yeah, actually Chrome allows to get resources, but we're not sure about
other browsers.
Add vote links

Make rating clickable if voting for story is still allowed (there's a
time limit).
Fix vote links href
Add ajax voting
Move story date to left column
Fix story voting: increment rating on response
Merge branch 'develop'
Increment version: 0.4.0