Copy original HTTP request headers

[gavinr]

• Removed conflicts from the changes from @jwoyame Copy original HTTP request headers, #175 #186. (Forward request headers #175)
• Also making sure the list of headers that are in Proxies should not return hop-by-hop header fields #362 are not passed along.

[bsvensson]

Thanks @gavinr :)

This PR has quite a few changes and potential for breaking unexpected things with the header changes. I tested it successfully with my 26 test cases. @MikeTschudi @jgravois et al - it'd be great and if you could also review/test.

I plan to merge this PR if I don't hear anything the next few days...

[esoekianto]

I remember we started passing thru all header value in the past during this issue #87 , Header, "Content-Disposition".

@bsvensson does any of your 26 test cases cover attachment scenario per issue #87 ?

If it does, we should be good.

[bsvensson]

@bsvensson does any of your 26 test cases cover attachment scenario per issue #87

No.

[MikeTschudi]

@gavinr, some questions and comments about the DotNet flavor, please.

• In forwardToServer(), the older code postBody.Length > 0?... remains; it's commented out, but is not needed even as a comment--the new code is better.
• In copyRequestHeaders(), how about executing headerKey.ToLower() once into a local variable? Even though the compiler can handle optimizing the 11 repeats of the call, it would make the code more readable.

@bsvensson

[gavinr]

Thanks @MikeTschudi - those changes have been made. Please take a look to make sure I have completed them in alignment with what you were thinking.

[MikeTschudi]

@gavinr, thanks!
@bsvensson, looks good to go from my perspective

[bsvensson]

Thanks @jwoyame @gavinr @MikeTschudi