[issue1341] printenv(1): don't allow '=' in name

[Matthew Dillon]

:After the recent libc changes, we no more allow environmental variables to =
:have
:an '=3D' character in their name. The printenv(1) utility isn't aware of th=
:at, so
:it embarrasses itself, along with misleading the user:
:..
:
:What do you think ? Ship it ?
:
:Cheers,
:Stathis

    No, it definitely should not exit if it is asked to display an
    environment variable with '=' in it.  It could print a warning
    to stderr, though, but I don't think it's necessary.  If the
    environment variable isn't supposed to exist then it won't find
    it.  If the environment variable does exist it is not printenv's
    job to check whether it is legal or not.

						-Matt