Remove word-wrap break-all

At between 645 and 750px long labels such as "case type: telecommunications" are too wide to fit in the checkbox container causing it to horizontally scroll.
There is currently no CSS solution that works across all (modern) browsers, the choices are:
- word-wrap:break-all which hyphenates all words in Firefox and Safari
- don't break any words and live with long words being cut off at narrower screen widths before the mobile layout kicks in
Merge pull request #30 from alphagov/fix-label-wrapping

Remove word-wrap break-all