Bug#739347: lintian: raise file-name-is-not-valid-UTF-8 to error in accordance with policy 10.10

[Helmut Grohne <helmut@subdivi.de>]

Package: lintian
Version: 2.5.21
Severity: wishlist

Dear lintian Maintainers,

Please raise the file-name-is-not-valid-UTF-8 tag to error level,
because the aspect it enforces has reached the Debian policy in section
10.10 in version 3.9.5 with a MUST clause.

I suggest the following info text (based on the original info text):

| The file name does not appear to be valid UTF-8. This violates Policy
| section 10.10.
| 
| Note that Lintian may be unable to display the filename accurately.
| Unprintable characters may have been replaced.

Note that the policy text has went further than the lintian tag in that
it requires members of $PATH to be representable as ASCII. You may want
to implement a tag enforcing this property as well.

Helmut