Highlight the status of extensions and contexts.
Option to create new context on notification
Highlight the target to drop the extension improves visualization.
Option to display the icon of the context or the extension icon on the popup
Adjustment to prevent errors for existing contexts
Best grip for contexts handle
Adjust the sortables
Merge pull request #22 from thiagomt/master

I'm merging this now and I'll do my fixes on the top of your changes. Thanks again, you are great!