net-vpn/openvpn: Upgrade package to upstream v2.4.1

Upstream has moved this package into the new "net-vpn" category, so
the references to it have been adjusted accordingly.

Patches iv_plat, redirect-gateway, and pkcs11-slot are carried forward
from 2.3.2 with minor formatting/context tweaks only.  The
large-passwords patch is newly introduced in 2.4.1 in order to support
passing long passwords from shill.

BUG=chromium:716913
TEST=manually connect to openvpn server
TEST=autotests
CQ-DEPEND=CL:491070

Change-Id: I1b02095ec5e38f517c189e34d679274223d937cd
Reviewed-on: https://chromium-review.googlesource.com/491107
Commit-Ready: Kevin Cernekee <cernekee@chromium.org>
Tested-by: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
23 files changed