Change tabs to spaces and format indentation correctly.

Separating this change to it's own PR so that actual code changes can be tracked. I simply used Sublime's 'convert tabs to spaces' functionality and 'format JavaScript'. Now identation is correct according to JSLint (and looks nicer :). After this is merged / accepted, I can add the other changes in #6.

Original pull request
https://github.com/solita/kansalaisaloite/pull/6