Added bootstrap component via bower

This will make updates easier
Added bootstrap SASS 2.3.1

Perhaps it might be a better idea to use bower, but adding these files
makes every other developer be able to build the site without bower, and
that is good.
Let sprockets find bootstrap and other assets.
Modifications to use bootstrap

Main modifications go in the template to use the sass bootstrap and
change variables around.
Fixes blog styling

It fixes almost all responsive problems.
Fixed transparency problem in homepage

Now the body can have an extra class. In this case the body in the
homepage has no top padding.
Added font-awesome

Also added a calendar icon in the news list of the homepage
Using font-awesome sass instead of css
Fixed margins in homepage when resizing
Fixed wrong merge during rebase
And I deleted the yield :(
Navigation sizes on mobile devices fixed

The special case here is navigation in the homepage
Merge pull request #44 from graffic/bootstrap

Using bootstrap