Merge pull request #71 from OneGov/jin-drop-python26-support

Theme not working with python 2.6
Added lang attribute to html.
Use html5 doctype.
Added condition for touch icons.
Move styles and script tags from body into head.
Flyout breadcrumbs should not be selectable with keys.
Updated changelog.
Merge pull request #77 from OneGov/jin-accessibility

Optimized accessibility.
Moved generate css into browserview.
Added timestamp to css url, for caching.
Pep8 cleanups.
Removed unused complexity.
Added fallback option to customstyles adapter get function.
Use absolute_url for customstyles css.
Updated changelog.
Set a new timestamp after save styles.