Addresses Data adapter error message issue raised in #62

- Fixes style bug
- Makes title wider
- Fix header's padding
- Remove confusing Data error description
- Tweak component description
Merge pull request #64 from locks/data-panel-error

Addresses Data adapter error message issue raised in #62
New send button icon and small mixin UI tweaks

- New send button icon

- remove double border between mixins

- match background color of collapsible headers (mixin__name) with
headers in Chrome inspector

- match disclosure triangle color with Chrome inspector and add some
white space
Merge pull request #67 from nummi/master

New send button icon and small mixin UI tweaks
View tree UI improvements
Add magnifying glass to inspect views on hover
View tree: add options to  show components and all views

Also added the ability to inspect a view's DOM element by clicking on its template

Done with @twokul
Show views and components in preview layer