GBIF Download: do no limit ourselves to a single country

[niconoe]

Currently, GBIF predicates are build based on a single country code found in the PTEROIS configuration object. To make the tool more useful globally, it would be good to be more flexible and allow other kind of filtering such as:

• multiple countries
• a bounding box (if possible, check GBIF documentation)
• global data (no country filtering)
• a continent
• ...

[niconoe]

This is now implemented (predicate building function moved to configuration).