Detect files regardless of filename extension case.
Currently during mummification we only detect known file types with filename extensions in canonical form, e.g. example.html. We do not support filename extensions in other cases, such as EXAMPLE.HTML. Although ideally we would encourage users to use canonical form to begin with, this may become difficult with other file times such as images () or other resources that may have been produced in an automated fashion (e.g. from a camera).
Detect file types regardless of filename extension case. This will probably involve normalization when registering mummifiers as well.
Normalize filename extensions during mummification. See AbstractPageMummifier.planArtifactTargetFilename(). We may want to put this capability in AbstractMummifier.planArtifactTargetFilename().