Create a NPM package for server side API

[Elorfin]

Create a NPM package for server side API and make the client application dependent to this package.

What to do :

• Create a new GitHub repository.
• Move server code into the new repository.
• Move server wiki into the new repository.
• Move server issue into the new repository.
• Create a package.json for client which will require the server.
• Update README.
• Publish package into NPM.

Why :

• Better decoupling server and client side.
• Better readability into the repositories (code, wiki, issues).
• Ability to manage releases separately for server and client.
• Users will be able to install the server API if they doesn't want the default UI.

[Elorfin]

Actually, I don't think the client need to be dependent on the API, because if we want to install the API on an other server, we will still install it (and all its dependencies) and never use it.

So it's better to not create this dependencies and make the client able to tell the user the API is not found.

[Elorfin]

API has been moved here.

It remains to be done:

• Move server wiki into the new repository.
• Publish package into NPM.