Hi all,

following the meeting we had here @Inria headquarters, I'll be backporting
some of the improvements we did in the launcher this last month regarding
the encoding of environment variables.

I've opened for this issue https://pharo.fogbugz.com/f/cases/22658/

We have already studied possible alternatives with Pablo and Christophe and
we have some conclusions and we propose some changes:

API Proposal for OSEnvironment
=========================


   -
*at: aVariableName *

Gets the String value of an environment variable called `aVariableName`
It is the system reponsibility to manage the encoding.
Rationale: A common denominator for all platforms providing an already
decoded string, because windows does not (compared to *nix systems) provide
a encoded byte representation of the value. Windows has instead its own
wide string representation.

   - *[optionally] rawAt: anEncodedVariableName*

Gets the Byte value of an environment variable called
`anEncodedVariableName`.
It is the user responsibility to encode and decode argument and return
values in the encoding of this preference.
Rationale: Some systems may want to have the liberty to use different
encodings, or even to put binary data in the variables.

   - *[optionally] at: aVariableName encoding: anEncoding*

Gets the value of an environment variable called `aVariableName` using
`anEncoding` to encode/decode arguments and return values.
Rationale: *xes could potentially use different encodings for their
environment variables or even use different encodings in different parts of
their file system.

Other Implementation details
=========================

   - VM primitives returning paths Strings should be carefuly managed to
   decode them, since they are actually C strings (so byte arrays) disguised
   as ByteStrings.
   - Windows requires calling the right *Wide version of the functions from
   C, plus the correct encoding routine. This could be implemented as an FFI
   call or by modifying the VM to do it properly instead of calling the Ascii
   version

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