rearrange css and css files for preview

• move preview-default.css include to PreviewManager
  because the styles can easily be used in plugins too
	like edit, close, save, admin module and add new entry buttons and more
• added buttons in "page admin filled_modules" style, just for consistency and discussion
improved details preview buttons etc.
improve style details
replace border by outline

• takes no space
Merge branch 'preview_styles'

use the same preview-default.css for all page types and plugins
resolve forgotten conflict
Merge branch 'master' of github.com:/rapila/cms-base

Conflicts:
	web/css/widget/widget.css