Survey.Editor becomes UMD library

We are using Webpack to make survey.editor an UMD library.
Editor supports the latest surveyjs library v0.10.0
All known bugs are fixed.

Property Editors are fully rewritten

Added new property editors and the code was heavily refactored
Support the latest version of surveyjs: 0.9.12

Support surveyjs v0.9.10

Introduce Undo/Redo functionality.
Fix all reported bugs.