Refactoring CommonsMetadata into smaller classes

Leaves a small static class for hook endpoints, makes everything
else non-static, with proper dependency injection, and follows
standard coding practices (one class per file, PSR-0 file/class names).

Also, renames InformationParser to TemplateParser since
{{Information}} is not the only thing being parsed.

Change-Id: Idfde96d3810402d201fa6337040b76aa43270750
Merge "Refactoring CommonsMetadata into smaller classes"