  \/ O - O N / O F F   I N D E N T \/

Leaves or enters indent mode. On entering Q initially, it is 'off'.

Parameter
 <yes/no arg> one of 'yes', 'no', 'true', 'false', 'on', 'off' with the obvious
	      meanings. Optional - if not specified the current state is
	      inverted. For details of what indent mode does, type 'H IM'.
