Add redirect-gateway/redirect-private to script environment

[AndersBlomdell]

While trying to get NetworkManager to obey the "push redirect-gateway/redirect-private" in the "--up"-script, I found that this was impossible since these commands were not visible in the environment. This is a first iteration trying to fix this.

Since "redirect_gateway=" was already part of the environment, the new environment variables are named "redirect_gateway_cmd/redirect_private_cmd"

[AndersBlomdell]

It might also make sense to change the code in options.c to validate that flags are compatible, e.g it's not clear from the documentation that the following directives are equivalent:

"redirect-private ipv6" == "redirect-gateway !ipv4 ipv6" "redirect-private" == "redirect-gateway !ipv4"

[ordex]

It might also make sense to change the code in options.c to validate that flags are compatible, e.g it's not clear from the documentation that the following directives are equivalent:

"redirect-private ipv6" == "redirect-gateway !ipv4 ipv6" "redirect-private" == "redirect-gateway !ipv4"

I don't think the above are equivalent. How did you conclude so?

Other than that it seems you want to extend the environment variable just for debugging purposes. I don't think this is a good idea.

If still interested in having this change reviewed, please send your patch to the mailing list, so that a broader audience can comment and have a look. Thanks!