Back StyleCop by JetBrains 4.7.1

Notes

• Automatically disable analysis if StyleCop.Analyzers is referenced in VS2015 (#20)
• Supports loading custom StyleCop addins. Specify location in settings (#18)
• Fix duplication of constructor summary XML doc element in Code Cleanup (#17)
• StyleCop issues now grouped under "StyleCop" in Inspection Results (#16)
• Separate Code Cleanup option to create XML doc stubs (#15)
• Not honouring settings when adjusting file header in Code Cleanup (#14)