document rejecting unicode and binary names

[rurban]

Package::Stash has a wrong understanding of the Perl API, it uses a crazy regex filter to disallow certain package names. perl5.16 allows the full set of binary characters as package name, even embedded \0 (it is now officially "binary (un)safe"), and it also allows unicode names.

This needs to be documented that it is ASCII only.

But I would rather call this drastic limitation a bug, and the regex filter should be rather left out, and I would provide a Package::Stash::ASCII module with this filter enabled.

Not talking about the wrong setting of the utf8 flag on the names. This is a seperate ticket already.

[ribasushi]

See also 1st paragraph of p5sagit/Sub-Name#4 (comment) and p5sagit/Sub-Name#4 (comment)