[WIP] Adding navigating to clusters and resource pools

Label as WIP.  I'd like comments on using quadicon for Clusters and Resource Pool Icons.
this `if` chain could be reduced to a reusable function. Something like:

```python
def any_in(items, iterable):
    return any(item in iterable for item in items)

if any_in(["parent", "Capacity & Utilization", "Timelines", "Show tree ...", "Show Host ..."], links[link].title:
   # do stuff
```


That `any_in` could live in some `utils.` submodule, let's say `utils.langext` or whatever. We could put all helper functions like this one in there to be easily available for anyone.

@seandst @weissjeffm ? ^