- Ensure that waiting on lock times out so that we don't lock
up a thread when the client is gone.
- Add an experimental folder to matdbg/web/ for the new
UI work.
- Use a hanging-GET approach to reduce dependency on websockets.
- Also add mutex to protect access to MaterialRecords, which is
written to/read from from multiple threads.
The websocket code for parsing the EDIT command is pretty verbose.
Proposing that we move to a HTTP POST request instead.
Also moved the API handler code out of DebugServer.h for clarity.
