only raise error in connect if we don't have a 'connect fail' callback
Merge pull request #136 from enotodden/connect-noraise

Only raise an error in IOStream:connect if we don't have a 'connect fail' callback.
Clarify wording for async.task.
Cleaned up multipart parsing code.
Merge branch 'test-no-cache-buffered-ptr'
Merge branch 'master' into windows-support