Update CodeMirror, AngularJS dependencies and UI.Codemirror itself

This webjar is quite old, so I updated the versions of CodeMirror (4.3), AngularJS(1.2.19) dependencies and UI.Codemirror (0.1.5) itself to the latest stable ones. And tested the changes on my setup.
In the future please keep this as `HEAD` because Maven does the actual release.