Make items on reserve not requestable.

Based on feedback from Access Services:
```
Items that are currently on reserve and checked out on reserve should not have a request hold/recall link.  
Items currently on reserve are first come, first serve
```

### 4004319 Before
![4004319-before](https://cloud.githubusercontent.com/assets/96776/4397382/e2b6c1a2-4441-11e4-9c2b-3ee2f5539227.png)

### 4004319 After
![4004319-after](https://cloud.githubusercontent.com/assets/96776/4397383/e2bcde66-4441-11e4-86c0-e001a090528f.png)