FLUME-1834. Flume Userguide is missing some memory channel props.
FLUME-1834. Flume Userguide is missing some memory channel props.

(Alexander Alten-Lorenz and Mike Percy via Hari Shreedharan)

tmgstevens/flume,szaboferee/flume,iaiengxia/flume,tinawenqiao/flume,tmgstevens/flume,tmgstevens/flume,tmgstevens/flume,iaiengxia/flume,iaiengxia/flume,tinawenqiao/flume,tinawenqiao/flume,szaboferee/flume,szaboferee/flume,szaboferee/flume,iaiengxia/flume,tinawenqiao/flume