Add documentation how to create your own Toolbar
Fix placeholder
SF
Introduce new classes for toolbar and buttons.

All toolbars will have alloy-editor-toolbar class and
all buttons will have alloy-editor-button class.
Add btn-group class to toolbar-add
Align toolbar add to buttons container
Fix brainless markdown lazy ordered lists
Minimize css and js files before release
Update package file with gulp-ignore package
Add prevent-minimize option

Prevent source minimizing on release
Remove obsolete gulp task
SF