coq-lsp support

[whonore]

Very experimental, but mostly functional. Currently requires vim-lsp.

TODO:

• Handle multiple files correctly
• Support Coq markdown (.mv) files
• Figure out a better solution for showing proof checking progress
• Clean up dead code
• Experiment with other LSP clients

[ejgallego]

Behavior with 0.1.9 should be much better suited for CoqTail, including a new serverStatus notification which you can use instead of fileProgress.

Also set the checking to lazy mode, and send the viewRange notification to the server, that will provide very good latency properties without the overhead of full-document continuous checking.

[whonore]

Thanks, those sound like very nice improvements. I'll definitely take another look at coq-lsp when I have some time.