Adds _billiard.readv(fd, list_of_buffers)
Pure-python implementation of Connection.send_offset
_billiard.read: Version of os.read that supports the Py_buffer interface
C send_offset now supports new buffer interface
Reverts change a70d245e89ed1fe24ad0ead3b74fa74fea9c141b (Closes #77)
Remove readv experimentation replaced by read+buffer
Bumps version to 3.3.0.6 and updates CHANGES.txt
flakes