Closes #3934

Issue ternjs/tern#668

Issue #3438

Adding a CodeMirror option for controlling how long the ternTooltip should be visible before closing

Tern completion for required module returns name (module wuith quote)
and displayName (module without quote). This PR gives the capability
to display completion for required module without quote.

I noticed that the image that accompanies auto-completion suggestions
when the tern addon is active gets cut slightly, because the default
line height is slightly smaller than the image height.

This change above ensures that the line height is bigger, hence
ensuring that the image is fully shown.

This PR initialize docs before creating tern server instance, because
in some case, tern server creation call getFile which use docs.

I have this case by using requirejs tern plugin + custom plugin which
defines modules :

```json
{
    "!name": "delite",
    "!define": {
      "!requirejs": {
        "delite/register": {
          "!type": "fn(tag: string, superclasses: [], props: ?) -> fn()",
      }
    }
  }
```

Issue #3308

Easiest to see the difference on touch-enabled device. Go to Tern demo
page (link below), click on a variable name and press Ctrl+I. Now pan
the editor's content. The tooltip stays at a fixed position, whilst
the variable name detaches and moves off.

The fix listens to scroll and blur, switching the tooltip off.

Issue #3055

Opening the documentation in the same window navigates away from the
code editor.

Issue #2644

Bumping them for every release just adds too much git
noise and history blowup.

Closes #2000

Create Tern request with optionnal pos to manage for instance tern
hover. See demo at
http://codemirror-java.opensagres.eu.cloudbees.net/codemirror-javascript/demo/javascript-all.html

Closes #1811

Issue #1799

Issue marijnh/tern#200