Support duplicate x509 field values in environment

Support duplicate x509 field values in environment

As reported in trac #387, an x509 DN can contain duplicate fields.
Previously, we would overwrite any previous field value with a new one if
we would process a second same-name field.  Now, instead, append _$N,
starting at N=1 to the name for each consequent field to export all fields
to the enviroment.

v2 - make better use of const qualifiers in env_set_get(), and use strcpy()
     instead of memcpy() in setenv_str_incr()

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Selva Nair <selva.nair@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <CAA1AbxLoZpanyqfpJuroMeOj_M=gU5JB+pqZqRxYqaiNP754-g@mail.gmail.com>
URL: http://article.gmane.org/gmane.network.openvpn.devel/10654
Signed-off-by: Gert Doering <gert@greenie.muc.de>