Copyrights refactoring

[damisul]

Replaced copyrighted column in Expressions table with enum intellectual_property.

• Updated Manifestation CRUD pages
• Updated TextAPI to accept array intellectual_property_types instead of is_copyrighted
• Extracted common view code used to render intellectual property info with into a shared partial and reused it on several pages.
• Updated Admin#missing_copyright action to render works with unknown intellectual property

NOTE

Still work in progress. People table is not changed yet.