Fixed

• Some code formats where not being properly colored.
• Show release events in the news feed.
• Update all icons (Octicons v3.2.0).
• Don't show references to nonexistent commits in issues.
• If an issue is closed from a commit, show the commit in the event.
• Improve rendering of some markdown files.
• Fix bug that hid files with same name but different case.
• Some minor bug fixes.
• Some minor UI fixes and improvements.