VSCoq Language Server

This is a language server for Coq speaking LSP with a few additional messages which are VSCoq specific (e.g. declaring a point of interest, printing goals).

• SEL is a simple event library used to handle I/O
• DM is a document manager for Coq with support for delegation via SEL
• vscoqtop is a Coq toplevel speaking LSP based on DM and SEL