Multi-server model

[laughedelic]

Ensime was added a while ago (but not exposed): #3, Dotty LS got in recently too: #48, but the way it worked was very cumbersome: user needs to choose 1 server he want to use all the time and when you want to switch, you have to reload the plugin/editor.

This plugin makes some refactoring to make different servers more obvious in the code and adds new feature: automatic choice of language server based on the project setup:

• if .ide-dotty-artifact file is around, it's a Dotty project
• if .metals folder is around, it's a Metals project
• if .ensime file is around, it's an Ensime project
• otherwise launch default server and warn user to setup the project

and the server gets chosen every time you open a new project in Atom.

User can choose default server in the settings. Probably it's better not to launch any server at all if the project is not setup yet. So far none of the servers can setup themselves completely autonomously (i.e. they require user to use some sbt plugin and run some commands, see https://github.com/scalacenter/load-plugin).

[laughedelic]

Better notifications:

And the case when user can choose which server to launch:

[laughedelic]

Better new project warnings:

• auto == true & default == none:

  

• auto == true & default != none:

  

Probably they look too similar... 🤔 I'll fix it later.

Plus the "muted" case: auto == false & default == none