This PR sets up rsync module per drive for swift object servers. This
improves resource distribution, and also allows us to utilise rsync
module changes to prevent disk writes to specific drives when they begin
filling up.
Enable this option by setting "swift_rsync_module_per_drive: True", this
will still default to False to match upstream defaults. Additionally the
rsync max connections has been increased to match upstream defaults.
Additionally we include rsync.d/*.conf files by default and set this
directory up, so that we can add individual configuration to disable
specific drives.
Change-Id: I2019cade5bf5f2878497d30ce738dff07786fa64
53027de8c8