Merge pull request #23 from stop777/master

Leading spaces in header value not stripped
Fixed async process_func setup
Merge remote-tracking branch 'origin/master'
Revert "Fixed process_func setting in AsyncClient.start"

This reverts commit c07e8ca2dbe23f3c6c00454b92c941be30c40046.
Merge branch 'master' of https://github.com/Lispython/human_curl