Upgrade Presentation Layer

[spjmurray]

It felt like too much presentation stuff was being repeated in each of the widgets so I've moved as much of this as I can into the application css, so you change one, you change them all. I was slightly horrified by the absolute positioning stuff so migrated to the far more elegant flex-box model. Various other cleanups and little bit of sparkle ;p

[spjmurray]

Here's how it looks https://incubator.storage.datacentred.io/dashing-icinga.png Hopefully I've not gone too modern (e.g. with the standards I am using) or too distasteful (with the pimp mode stuff) for Michael :smiling_imp:

[dnsmichi]

Sweet, thanks 👍

[dnsmichi]

Fancy, I like your style a lot ❤️

[dnsmichi]

Top, thanks 🥇