Revert "handle timestamp more flexiable"

This reverts commit 9922068c624f64c738cdad91578ce36e52351695.
Revert "handle the timestamp part neatly"

This reverts commit 6c5a8bd2825978c562b3e19264cbb6f4ec51bcc7.
Merge branch '4.0'
add initial support for upload directory
pass QByteArray for QHttpPart::setBody because it accepts QByteArray by default