Nutrition IA

This is still a WIP, but opening the PR because it's working and I could use input about how to clean up some of the triggering/relevancy stuff. I'm sure there will still need to be UI tweaks as well.

![screen shot 2014-10-19 at 5 36 54 pm](https://cloud.githubusercontent.com/assets/126358/4694833/2a412a18-57d8-11e4-862e-7fbc52799cc1.png)
![screen shot 2014-10-19 at 5 37 59 pm](https://cloud.githubusercontent.com/assets/126358/4694837/3b0596ae-57d8-11e4-8f3b-bc44a429adcb.png)

@russellholt @jagtalon @chrismorast 
Could you do this guarding the other way around? It's easier to figure out where and how to add additional relevancy checks if the guards return early instead of the "work cases." A named capture might also make it easier to adjust if we need to use more context later to reason about what is happening:

```perl
$_ =~ /^(?:how|what)?(?:'s | is | are | many | much )?(?:the )?(?:total | amount of )?$attribute_regex\s?(?:are | contained )?(?:there )?(?:in )?(?:a |an )?(?<food>.*)/;

my $food_item = $+{'food'} || '';

return unless $food_item;

return $food_item;
```