stunnel: Bring it back at v5.10

stunnel: Bring it back at v5.10

From: Michael Haas <haas@computerlinguist.org>

* init script no longer creates certificates (consider client mode as use
  case)
* patches/010_fix_getnameinfo.patch: Fix getnameinfo signature
* patches/011_disable_ssp_linking.patch: Disable -fstack-protector as it
  is not always available in OpenWRT
* old patches (in oldpackages) no longer necessary
* remove libwrap dependency
* remove libpthread dependency
* respect CONFIG_IPV6
* init script uses procd
* sample stunnel.conf runs in client mode - prevents start failure,
  does not require cert

Possible enhancement: automatically generate certificate as done in
uhttpd. However, as client mode is a possible use case, I'd rather not.
Additionally, stunnel may use several certs with user-defined locations
and we can't easily set a cert location via command-line args.

The package is based on
https://sites.google.com/site/twisteroidambassador/openwrt/stunnel

Signed-off-by: Michael Haas <haas@computerlinguist.org>