commit 3e38992fbee06974da202e8491902dbfb80e2e2d
author Todd Wang <toddw@google.com> Thu May 14 23:09:38 2015 -0700
committer Todd Wang <toddw@google.com> Thu May 14 23:09:41 2015 -0700
tree d0b87f5d4c5b68c717f992fb4ab6133ef7612a2f
parent 3bb46f5d7d26b272a26c74700c0191346943f3a6

ref: Add support for cmdline.Env.Vars

This adds envrionment variable support to cmdline.Env, and also
updates some programs to use this support.  The main benefit of
using cmdline.Env.Vars is that it makes testing easier, since you
can just pass in your own map.

We represent environment variables as map[string]string, which is
a nice simple form for lookups and mutations.  Originally I was
planning on using *envvar.Vars, but the delta-tracking support is
probably unnecessary, and the native Go map syntax is nicer.

A subsequent change will update the v23.Init and test.InitForTest
mechanisms to support explicit passing of args and envvars, and
will take advantage of this support.

MultiPart: 2/2
Change-Id: Ic9bb9a71b05fd73dafa630f069236c716ee33fb2