refactor(grunt): Ext JS 5 refactor update & cleanup.

**TODO** enable JSHint for packages.
refactor(grunt): cleanup

 * deleted:    app/AppInspector/resources/Readme.md
 * modified:   grunt/aliases.js
 * modified:   grunt/changelog.js
 * modified:   grunt/chromeManifest.js
 * modified:   grunt/copy.js
 * modified:   grunt/exec.js
 * deleted:    grunt/fileblocks.js
 * deleted:    grunt/watch.js
 * modified:   package.json

 > Chrome CSP forbids inline code, and this is not subject to override. Your 'unsafe-eval' does not address the issue, and 'unsafe-inline' that would've helped will be ignored by Chrome. (*[source](http://stackoverflow.com/a/23218007)*)

And as Sencha CMD will put the *microloader* contents into `index.html` it violates this.
We have to find a way to replace
```html
    <script type="text/javascript">var Ext=Ext||{};Ext.manifest="app";Ext=Ext||window.Ext||{}; /* ... */ </script>
```
and again use the *microloader*.

See also
 * https://developer.chrome.com/extensions/contentSecurityPolicy#JSExecution.
 * http://www.html5rocks.com/en/tutorials/security/content-security-policy/
style(AI): comments & cleanup

 * modified:   app/AppInspector/bootstrap.css
 * modified:   app/AppInspector/bootstrap.js
 * modified:   app/AppInspector/bootstrap.json
style(AI.view.about.About): added »powered by«

 * modified:   app/view/about/About.js
 * modified:   packages/AppInspectorTheme/sass/src/panel/Panel.scss
Merge pull request #113 from stoe/refactor/grunt

refactor(grunt): Ext JS 5 refactor update & cleanup.
Merge pull request #114 from stoe/poweredby

added "powered by Ext JS ..."
Fix for microloader, which was breaking the Chrome extension distribution.
Merge pull request #115 from arthurakay/ext5_upgrade

Fix for microloader