Bug 911127 - Repair DebuggerServer loading on B2G. r=dcamp
New markup structure for the markup-view inspector.
This allows for tags to have a full edge-to-edge line.
So highlight and click areas are easier to use.

- First integration of the new markup behind the markup-view. Working ok so far
- splitting files and wiring deps
- making vertical spacing consistent with the rest of the devetools