always run our little node HTTP proxy locally to constantly test HTTP proxy support which we'll have in production - issue #904

explicitly call .removeAllListeners() during http forwarding to eliminate memory leak.  closes #839 (with extreme prejudice)

explicitly call .removeAllListeners() during http forwarding to eliminate memory leak.  closes #839 (with extreme prejudice)

disable http agent in http_forward - it has been capping us at five simul forwarded requests per backend process (dbwriter, keysigner)

on a hard connection error during http forwarding, don't end the client reqeust, instead let the client formulate the error code and message

disable request parsing/validation on browserid (aka "webhead") - all will be performed on the dbwriter (aka "secure webhead") - issue #460 (NOTE: request validation on webhead too requires a better session cookie implementation)

initial implementation of request forwarding, cookies set from dbwriter are still not being properly passed through - issue #460

everything else is filtered.  Things like Content-Encoding shouldn't be blindly
forwarded.

Also when forwarding responses,  ensure proper casing of headers.

issue #460