Add live availability lookup to record view and search results

Closes #292 Closes #320 

### Screenshots/Examples

**Note: All screenshots taken agains production live lookup unless otherwise noted

#### 3956413 (checked out)
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![3956413-checkedout](https://cloud.githubusercontent.com/assets/96776/3477309/33355c78-0316-11e4-889d-a6beb1cb517b.png)

#### 8442676 (available)
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![8442676-available](https://cloud.githubusercontent.com/assets/96776/3477311/40e6a516-0316-11e4-868b-6ccbce406d9a.png)

#### 9855327 (current location + due date + request link from live lookup) *dev server only*
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![9855327-current-due-date](https://cloud.githubusercontent.com/assets/96776/3477318/645a4aa2-0316-11e4-95a9-a073a12d86f9.png)

#### 4669728 (due date w/o request link due to non-requstable type)
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![4669728-due-date-no-request](https://cloud.githubusercontent.com/assets/96776/3477326/88de950e-0316-11e4-8419-081c97f1aac8.png)


Hmm, well, unlike the `marc_xml` this is unlikely to need to be re-used anywhere.  We have various code around the app to process marc and mods in various ways that lend themselves to reuse, however; my hope would be that this is the only code that would ever touch the live-lookup XML, so extracting for reuse seems like unnecessary overhead.

If we end up needing to parse this XML response in another piece of code then I would support abstracting this into a fixtures module at that point.