Support UTF-8 in man pages

Tries to detect when the calling module includes `utf8.pm` and

- enables an `encoding(UTF-8)` flag with `Path::Class::File->spew()`

- inserts `=encoding UTF-8` as the first statement in the generated
  pod file

I am not a perl guru. So, this might be brittle, have unwanted side
effects and all other kinds of bad things happening, but it works
for me (TM).
remove mouse tests
enforce utf8 for all sources
add test for utf8 sources
Merge redmine-review-feature-452-support-utf8-source-for-pod-and-man
reflect changes
use line fold
Merge redmine-review-feature-453-use-text-linefold-instead-of-text-wrapi18n
reflect changes
Add version in Changes
Update version DistZilla
update mkdn
Merge redmine-release-v4.010
Merge redmine-release-v4.010