Added parsing of hausdorff distance

[DavidWatkins]

There was no functionality to parse the computed hausdorff distance between two meshes. I have added a parse_hausdorff function inside of compute.py. This creates a dictionary of five values, the min_distance, max_distance, mean_distance, rms_distance, and number_points which are returned by the call. Can you pull this into the main branch?

[3DLIRIOUS]

Thanks a lot for adding this feature!

I did have a question regarding the addition of the default_geometry, default_topology and default_hausdorff_distance functions. It appears that these were added in order to initialize self.geometry, etc. when the Filterscript class is called, however I don't think that this is desired. The self.geometry, etc. attributes should not exist unless the measure_geometry, etc. functions are called and the attributes are populated with real data. Am I perhaps missing a consideration where initializing these for every script would be desirable?

[DavidWatkins]

I was trying to make sure the code passed my linter. Namely I got this error otherwise: "instance attribute is defined outside the init method". This is not something that is strictly necessary and definitely can be omitted for the sake of merging this into master.

[3DLIRIOUS]

I read up on that error, and I agree that it is good practice to initialize all variables in init, even if just for the sake of readability. However, I think that these values should be initialized as None instead of default values. I would prefer to keep the initialization of the defaults inside the parsing functions. Would you mind making this change before I commit?

[DavidWatkins]

Already done. Let me know if there is anything else you recommend otherwise I think it's good for merging.