Resqpy

This change adds a class method to Surface which allows creation of down-sampled version of an existing Surface. A random subset of points from the source (fine) surface are selected and re-triangulated to yield the new surface.

When using the rq_import module to import surfaces, the code would add a title composed of a shorter name followed by 'sourced from' and the original file path. This patch changes that behaviour so that the citation title is the shorter name only, and the original file path is added to extra metadata with the key 'source'.

Note: the shorter name is derived as before, by removing any extension from the file base name.

This patch improves the PointSet.from_irap() method to (by default) exclude the last point in the input file if it is close to triple 999.0.

This patch fixes a minor bug affecting the property_parts() and property_part() function when facet information is passed without a property kind.

This patch introduces a method to the TetraGrid class to set the cell face handedness attribute based on the geometry. This initial implementation is likely to be slow for grids with a high cell count.

To use the new functionality, call the following method for a new TetraGrid, after setting up its geometry but before writing hdf5 or creating xml:
`TetraGrid.set_cell_face_is_right_handed_from_geometry()`

This minor release improves the behaviour of the GridConnectionSet.append() method and adds a higher level class method – from_gcs_uuid_list() – which merges a list of grid connection sets into a single new grid connection set, optionally merging properties, and optionally creating the new GCS in a different model to the originals.

The PropertyCollection class also gets a new convenience method – add_similar_to_imported_list() – which facilitates a new property to be created by defaulting all the metadata to a copy of the metadata for an existing property, meaning only those metadata items which are different need be specified.