Add cut/copy/paste events to list of ones that our dispatcher with automatically catch. This is needed to support two-way binding from contenteditable divs.

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Add keyup/cut/paste handlers for enyo.RichText that update the value property to allow two-way binding to work.
Fixes ENYO-2113

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Remove getValue(), which is no longer needed and prevents bindings from working.

Standardize on new get() syntax for property access.

Enyo-DCO-1.1-Signed-Off-By: Gray Norton (gray.norton@lge.com)
Merge pull request #258 from enyojs/ENYO-2113

Fix for ENYO-2113: Enyo - Onyx - Inputs - cannot enter text into RichText boxes.

Also makes RichText controls bindable.

Reviewed-By: Gray Norton (gray.norton@lge.com)