Boundary database has problems

The first boundary database of Luxembourg has some problems:

• The boundary IDs LUX-0 to LUX-11 appear twice. The boundary_id field should be unique.
• The boundary IDS for the 30-arcsec cells use an _ instead of an hyphen.
• The all-country boundary should have a predefined name, e.g. LUX-ALL or LUX-COUNTRY (see #1 (closed)).
• NAME_0 and ID_1 are missing.
• All field names should be lower case as we use this as database standard.
• The OSM relation ID(s) should be added to a text field, either one or in the case of multiple IDs separated by a comma or semicolon.
• The ID and NAME fields for 30-arcsec cells should refer to the districts and country the center point is located in.
• The main ID field should be called id instead of boundary_id. So far we have an id in every table but refer from other tables to it as boundary_id or similar.

I also wonder what values are stored in CELL_X and CELL_Y?

\rfc @shinde @tara