Entangled and VS Code

[EmiliaJarochowska]

If one deletes a file using VS Code, it confuses entangled, so one gets

WARNING  File `runs/variable_sl-plot.jl` in DB seems not to exist,
                    but this file is managed.
                    This may happen every now and then with certain editors that
                    delete a file before writing.

followed by errors and a crash.
Since I had entangled running in the background, I ended up making some modifications before realizing that entangled had crashed.

[jhidding]

I'm going to deprecate the use of entangled watch in favour of using the watchman utilities. This means that running a watch-and-build loop will be outside the concern of Entangled. I may keep entangled watch as a convenience, just like entangled new is a convenience layer for copier.