create a detach helper and use detach helper in replace of process.nextTick
accept charset for x-www-form-urlencoded content-type

update the readme
update the tests
Merge pull request #1159 from seanstrom/support/rm-charset-contentheader

accept charset for x-www-form-urlencoded content-type
in post can send form data and use callback
Merge pull request #1171 from MiroRadenovic/master

in post can send form data and use callback
change detach to defer
Merge pull request #1168 from seanstrom/support/use-setimmediate-when-available

create a detach helper and use detach helper in replace of nextTick