Until we can get our own RequestServer infrastructure up and running,
running the TLS and HTTP code in-process was causing lots of crashes
due to unexpected reentrancy via nested event loops.
This patch adds a simple backend for HTTP and HTTPS requests that simply
funnels them through QNetworkAccessManager.
On high-dpi systems QT will automatically scale up painting operations.
This results in an ugly blurry browser window surrounded by a nicely
scaled window frame. This patch applies an inverse scale to the WebView
widget, ensuring the painting and mouse events are lined up and draw
with a 1:1 pixel ratio with respect to the display's device pixels.
