align erb backend with builtin

- fix unclosed icon tag in admonition
- use "prop: val;" syntax for inline styles
- cleanup some endlines
align haml backend with builtin

- remove chomp on content
- use "prop: val;" syntax for inline styles
- cleanup endlines
- add author class to author span
- add email class to email span
- use br after version in footer if last update is present
- honor sectnumlevels setting