Add Support for converting ENV to UTF8. Issue #36

[ajbrowe]

• Add Support for converting ENV to UTF8. Issue Handle %ENV #36
• Add POD for ENV changes
• Restore %ENV after unimport

---

This is the first PR on behalf of Adestra for the CPAN PRC for January 2018

There will be a performance hit to using a tied %ENV, however In my experience %ENV is not accessed on such a scale that the performance will be an issue. perhaps I'm wrong.

It is possible to disable the tie with NO-GLOBAL or no utf8::all

[Leont]

I think this implementation is both incorrectly scoped (it should only decode/encode when the caller is using the utf8::all pragma), and unnecessarily poorly performing (because it decodes all entries, even when typically few are used).

Decoding (and encoding) on request would automatically solve the latter issue, and will solve the former too if done well.

[ajbrowe]

Thanks for that, will see what we can do about that.