receive header folding

[sbeckeriv]

Dearest Reviewer,

I looked at issue #81 and found that the CRLF was adding whitespace to the text during the integer parsing. I added a trim call to the error flow and try parsing again. I did this because it appears to be the exceptional case and normal flows will not take the cost of trim with every process. I can move the trim back out.

I used the failing test that was provided.

Thanks for your time Becker