isolines labels are different between mac and linux

[doutriaux1]

@dlonie @aashish24
Labels are not at the same location between the two OS
baseline comes out completely different between mac 10.8 and ubuntu

see:
https://open.cdash.org/testDetails.php?test=321953990&build=3742819

[doutriaux1]

@williams13 on mac I do get the aeqd vector test errors. I just turned them off for now since the diff is just a line that is not drawn on Linux and the vectors are not drawn at all when projecting anyway

[doutriaux1]

@dlonie @aashish24 my bad I had forgotten t update the baseline on my mac... it's all good!