Check to see if the RHS in Chebop2 is the zero chebfun2.  If it is then do not change the handle for the PDO because we want the user to see it in the display method.
Adding rank info to the chebop2/display method.
n.rhs -> N.rhs.
Merge remote-tracking branch 'origin/development' into feature-chebop2-display
Increase tolerance.
Merge pull request #1187 from chebfun/feature-chebop2-display

Feature chebop2 display