Clickover plugin not compatible with bootstrap 3

The [clickover](https://github.com/lecar-red/bootstrapx-clickover) plugin has not been updated in a year and is not compatible with bootstrap 3. (See, e.g. #3424)
I'm seeing another weird issue:

```
1. Select a content item in my library
2. Click `Share`. The popover shows as expected
3. Click the notifications icon. The share popover disappears and the notifications popover appears as expected
4. Close the notifications popover
5. Click the `Share` button again. The share popover no longer triggers
```