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-79: Removed old and unnecessary code artifacts probably
installed by the Mustache-plugin
DDBNEXT-74: Fixed errors found in code review DDBNEXT-53
Merge branch 'DDBNEXT-79' into develop
DDBNEXT-79: Hot-Fixed build path problem when the last domain class was
deleted.
Merge branch 'develop' of
https://github.com/Deutsche-Digitale-Bibliothek/ddb-next.git into
DDBNEXT-75

Conflicts:
	grails-app/controllers/de/ddb/next/ErrorController.groovy