Resize textboxes on service availability page

- The textboxes should indicate by their size how much content is expected
- 20 words is too many to easily count by eye, so we should provide a word count
- Also makes sure that the height of textboxes cuts the last line of text in half horizontally so that it's clear that there's more content than the box can fit

![screen shot 2014-10-06 at 16 10 32](https://cloud.githubusercontent.com/assets/355079/4527961/2f53a5ca-4d6b-11e4-8bd7-b6a133e7b189.png)