InputLabels
-------------------------------------------------------------------------------------
Shows how to create input fields with floating labels and validation messages.

The sample defines CSS rules based on a "wj-labeled-input" class to create
input fields with floating labels and validation messages.

The labeled inputs are similar to text fields with floating labels implemented in
<a href="https://getmdl.io/components/index.html#textfields-section">Material Design Lite</a>
and to the "paper-input" element implemented in
<a href="https://elements.polymer-project.org/elements/paper-input?view=demo:demo/index.html&active=paper-input">Polymer</a>.

The CSS rules used in this sample take advantage of Wijmo's pseudo class extensions
which include "wj-state-focused", "wj-state-empty", and "wj-state-invalid".

The sample also shows how to use the Popup class to create modal dialogs containing
forms, and how to handle user submissions and cancellations.
