Package org.opengis.test.referencing.gigs

Implements the Geospatial Integrity of Geoscience Software tests.

Changes compared to GIGS files
The GIGS Excel files have been converted to CSV files, and some values have been edited in order to reflect the current values in latest EPSG database. We also increased the precision of some numerical values when needed in order to meet the GIGS accuracy requirements in test results. The changes are documented here.