Add ability to use context sensitive searches in primo

To do a context search on primo view, simply add this in the yaml

```yaml
CU:
  redirects:
    - /cooper
  tabs:
    all:
      default_precision: contains
      searches:
        default:
          contains: digital divide
          exact: little prince
          starts_with: global warming
      production:
          contains: different search
          exact: different search
          starts_with: different search
```

And add `bobcat_context: production` in your config.yml file.