[WIP] Improve Che IDE extensibility model

[vparfonov]

Problem

The current Eclipse Che architecture for the client side IDE is using GWT and Guice/Gin for the dependency injection. Eclipse Che IDE is composed of API Core functions and plugins. With GWT, all plugins are statically linked at compile time, it means that adding a plugin to the assembly requires to build each time this build take long time

Goals

1. Need to allow developer develop only own plugin and include it to the compiled Che IDE without rebuild all app
2. Make possible develop client-side plugin on pure JavaScript
3. Consider Che plugin as single artifact which contains:

• server side code;
• client side code;
• some meta information;

Tasks

• Investigate ability build each core module and plugin like GWT application (compiled to javascript) and embed them to the web app like ready to go resources Investigate ability build each core module and plugin like GWT application (compiled to javascript) and embed them to the web app like ready to go resources #8252
• Provide JavaScript API for each existing client side API developed with GWT technology with JsType feature Provide JavaScript API for each existing client side API #6647
• Generate JavaScript template for plugin Make it possible in easy way generate skeleton for JavaScript plugin  #7857
• Move directory with installed Che JS Plugin from the WS Master instance to the separate service Move directory with installed Che JS Plugin from the WS Master instance to the separate service #8221

[benoitf]

About #2, I would like to see what it will be before trying to do a direct 1-1 mapping.

I'm interested in the simplicity of the API and if it will match the full the loading/unloading sequence of a plugin

For reference, here are two documents I've provided
https://docs.google.com/document/d/1OcC8cnmPzwQybSi58OSQKTngXEqV46oFEyGn6phpB6U/edit
https://docs.google.com/document/d/1t7bOjC6MkgJdv14KSwcYqh2xBrWQWaYCgkatRUmZzfc/edit

[bmicklea]

@vparfonov can you please add and link the tasks in the Tasks section?

[slemeur]

Will be addressed by #8266