add option to emphasize first page of chapter
add background positioning ability to video
Make Background Video Positioning Work in Editor

* Attach to resize page type hook
* Do not measure body
add chapter specific classes to navigation
fix translation key for page pictogram title in editor
remove unneeded default
Merge pull request #151 from schoetty/emphasize_chapter_beginning

enable emphasis of chapter's first page
Merge pull request #194 from schoetty/page_type_i18n

Fix translation key for page pictogram title in editor
Merge pull request #176 from tf/background_video_positioning

Add Background Positioning Ability to Video