Make p and form tags in liveupdate updates display block.

:eyeglasses: @powerlanguage @chromakode @spladug

I removed this once before but it looks like it snuck back in with the redesign.

For many updates that are > a paragraph long we need to be able to break. Unfortunately this also means that the signature is on the next line for now. This is a quasi-urgent need requested by Mike. 

With this change the opening text for the Maker's Mark thread for example will look like:

![image](https://cloud.githubusercontent.com/assets/285920/2857280/cbc5c8a6-d175-11e3-886d-26b99acca6d4.png)

Without it it looks like:

![image](https://cloud.githubusercontent.com/assets/285920/2857283/d7b1f0ea-d175-11e3-9eff-178fe1fd3e02.png)

The username-on-separate-line thing looks like:

![image](https://cloud.githubusercontent.com/assets/285920/2857311/2362495e-d176-11e3-8199-c0f2bae2029b.png)

As opposed to:

![image](https://cloud.githubusercontent.com/assets/285920/2857316/31a2f798-d176-11e3-9aaa-0c2f128b4c02.png)

We can probably fix that in a followup change if we like.