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 the `-SNAPSHOT` since Maven does the release.