Timeline compressed history panel on detail page

[andrewvc]

This issue is a placeholder for our discussion around how to better integrate timelines onto the monitor details page. While our redesign (#79) adds the timeline visual, we're retaining the "History" panel on the bottom of the detail page, which doesn't address the central issues raised in #56 .

In essense, in the history panel we say things like the below:

the site was up 1s ago
the site was up 2s ago
the site was down 3s ago
the site was down 4s ago
the site was up 5s ago.

When we could say

the site is up now
the site came back up 2s ago
the site went down 4s ago

@katrin-freihofner would love your input on this one and possibly some rough sketches on how we can better display this. We have to keep in mind that geo locations and IPs are also a part of this, a site can be down in only one of those dimensions or up in only one of them, making visualizing this somewhat tricky.

[katrin-freihofner]

I'd like to emphasize long outages, maybe like this:

I also added the filter bar. This would enable us to filter for specific locations,...