Rename webview

This is basically what has been discussed elsewhere. I chose the name `ChromiumWebBrowser`, which I feel is quite much in line with the standard WinForms/WPF `WebBrowser` control naming.

For the sake of democracy, I didn't do this straight on master, so you have a chance to say :+1: or :-1:. :smiley: 

I also made some other minor changes while I was at it, but each one is in a separate commit (like we prescribe for others).