Admin panel - Add project - remove columns "Root map" and "Mapping file"

"Root map" and "Mapping file" can become a type in the "Map type" column. This makes the two columns with checkboxes, "Root map" and "Mapping file", redundant. "Name" column can be a bit wider.

added enhancement graphics; css; layout labels

created merge request !748 (merged) to address this issue

mentioned in merge request !748 (merged)

closed via merge request !748 (merged)

mentioned in commit fea10266