May DC release: browser notifications and accepted answer

Hi, Community!

Please meet  a new Developer Community UI release with new features and some bugfixes.

With this release we changed a color scheme to meet corporate colors more. 

We introduced browser notifications not to miss new posts on Developer Community. They would pop up only if you turn them on and only if you don't see the Community at the moment. 

Also we introduced the special inverse color for accepted answers. Like here:

Dear question authors! Please mark answers as accepted to make the world better (of course if there is an answer, you can accept).

We also fixed a few bugs.

Please provide your feedback regarding  the new version here in comments, and the new requests and bugs in a feedback group.