Refactoring in methods of action class
add @DATE(<date>[, <format>])@ syntax. Fixes #21

Syntax similar to bureaucracy. Difference: in the bureacracy the % needs
to be escaped, here using single % is fine.

Examples:
@DATE(<date>)@ formats given <date> with config['dformat'] setting
@DATE(@DATE@, %Y-%m-%e)@ formats @DATE@ with given format setting.