Fixes netty4 module's CORS config to use defaults

[abeyad]

Fixes netty4 module's CORS config to use defaults for http.cors.allow-methods and http.cors.allow-headers when none are specified. Currently, there was a bug where if no value was specified for http.cors.allow-methods or http.cors.allow-headers, an empty value was used instead of the actual defaults.

Note that this bug does not exist in the netty3 module.

[jasontedor]

I find tests that reuse local variables, e.g., because they are testing different setups, quite confusing. Can we break this into two tests or at least use some scoping so that it's less confusing?

[jasontedor]

It looks good, I left a comment about the test.

[abeyad]

@jasontedor Thanks for the review. I pushed e09791c to split the tests into two and I made a small change that enabled refactoring these tests to not create the more heavy-weight Netty4HttpServerTransport class but instead just build the CorsConfig.

[jasontedor]

@abeyad There are merge conflicts now, almost surely from the integration earlier this morning of the Expect: 100-continue test. Can you merge master in, resolve the conflicts, and push to this branch?

[abeyad]

@jasontedor I've resolved all conflicts with master, the latest has been pushed up

[jasontedor]

LGTM.

[abeyad]

thanks for the review @jasontedor