refactor(Ext JS 5): cleanup
refactor(grunt): grunt exec

removed Sencha Architect dependency from `grunt exec` subtask.
refactor(Ext JS 5): theming

 * modified:   app/AppInspector/packages/AppInspectorTheme/sass/var/Component.scss
 * new file:   app/AppInspector/packages/AppInspectorTheme/sass/var/container/ButtonGroup.scss
 * new file:   app/AppInspector/packages/AppInspectorTheme/sass/var/panel/Panel.scss
 * new file:   app/AppInspector/packages/AppInspectorTheme/sass/var/tab/Panel.scss
style(AI app): class comments

removed last Sencha Architect comment stubs.
added JSdoc comments instead.
Merge pull request #96 from stoe/ext5_upgrade

Ext JS 5 upgrade