Make Firefox Developer Tools compatible to Thunderbird

by Philipp Kewisch for Mozilla

I propose to modify Thunderbird to allow using all current remote features of the Mozilla Developer Tools. This includes the web console, debugger, style editor and network monitor. The key difference between my proposal and the past solutions is that no extra UI is needed within Thunderbird which might end up breaking because Firefox-specific features are being used. Instead, I will ensure the existing components are fully free of Firefox specific code and write the wrapper layer needed to make use of the backend components.