test: http complete list of non-concat headers

The original test was only testing some of the headers that shouldn't be
concatenated as per lib/_http_incoming.js, so now the full list is
there.

'content-length` gives a parse error if you set it to a string, so the
test for that header uses numbers.

PR-URL: https://github.com/nodejs/node/pull/3930


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>