This allows the same environment variables to be read, parsed, and used
from any API client as was previously handled in the CLI. The CLI now
uses the API environment variable reading capability, then overrides any
values from command line flags, if necessary.
Fixes#618
This strips out http.DefaultClient everywhere I could immediately find
it. Too many things use it and then modify it in incompatible ways.
Fixes#700, I believe.
Vault doesn't generate these, but in some cases Go's internal HTTP
handler does. For instance, during a mount-tune command, finishing the
mount path with / (as in secret/) would cause the final URL path to
contain .../mounts/secret//tune. The double slash would trigger this
behavior in Go's handler and generate a 301. Since Vault generates 307s,
this would cause the client to think that everything was okay when in
fact nothing had happened.
create our own. This avoids some potential client race conditions when
they are setting values on the Vault API client while the default client
is being used elsewhere in other goroutines, as was seen in
consul-template.
