Add mime converter support for XSLT as requested in #5392 and tweak XSL mime type definition.
Add mime converter support for XSLT as requested in #5392 and tweak XSL mime type definition.

See [comment:ticket:5392:1]

git-svn-id: eda3d06fcef731589ace1b284159cead3416df9b@5901 af82e41b-90c4-0310-8c96-b1721e28e2e2

netjunki/trac-Pygit2,walty8/trac,netjunki/trac-Pygit2,jun66j5/trac-ja,jun66j5/trac-ja,walty8/trac,netjunki/trac-Pygit2,jun66j5/trac-ja,walty8/trac,jun66j5/trac-ja,walty8/trac