use more specific mimetypes for CSV and TSV export of reports in consistency with the query module (fixes #2669)
use more specific mimetypes for CSV and TSV export of reports in consistency with the query module (fixes #2669)

git-svn-id: f68c6b3b1dcd5d00a2560c384475aaef3bc99487@4471 af82e41b-90c4-0310-8c96-b1721e28e2e2

exocad/exotrac,dokipen/trac,dafrito/trac-mirror,moreati/trac-gitsvn,dokipen/trac,dafrito/trac-mirror,moreati/trac-gitsvn,moreati/trac-gitsvn,exocad/exotrac,dokipen/trac,dafrito/trac-mirror,moreati/trac-gitsvn,dafrito/trac-mirror,exocad/exotrac,exocad/exotrac