Add functions for issuing commands to ceph mgrs with
MgrCommand and MgrCommandWithInputBuffer, implemented simliarly
to the other *Command style functions.
Signed-off-by: John Mulligan <jmulligan@redhat.com>
Organize the rados package a bit more by moving functions that wrap
rados_xyz_command functions into a dedicated file. Move related test to
a separate file as well.
Signed-off-by: John Mulligan <jmulligan@redhat.com>