DDBNEXT-57 and DDBNEXT-74: Error-Handling 404 and Error-Handling 500
without stacktrace in productive environment
DDBNEXT-57 and DDBNEXT-74: Fixed the view files to show the error
message in the title like on production. Removed old and unneeded
error.gsp
DDBNEXT-74: Fixed errors found in code review DDBNEXT-53