Bug fixes:

• Ensure the swagger doc is semantically correct (#3390) @ubolator
• Fix crashes with some plugins (#3401) @Kukks
• Fix crash of payment request list (#3392) @NicolasDorier
• Reference correct payment type definition for webhook events in Swagger docs @ubolator
• Fix pay button type comparison (#3403) @dennisreimann
• No JS error in crowdfund if canvas unavailable @NicolasDorier
• Bump z-index on header (#3393, #3377) @ubolator

Improvements:

• Delete user preferences cookie on logout (#3379) @dennisreimann
• Pay Button Alert: Add missing alert-link classes (#3397)
• Fix pay button type comparison (#3403 #3403) @dennisreimann
• Various CSS UI adjustment @dstrukt