Allow box select with CTRL pressed nothing is under mouse cursor
Due to historical reasons, box select with CTRL down has not worked since 2011 (https://www.simantics.org/redmine/projects/simantics-platform/repository/revisions/23288).
There is no longer reason to have this in place. The code has been refactored quite a lot since. The box selection event handler routine has been separated from the other event handling and it can separately check for shift/ctrl modifiers while previously the since modifier check guided all the different event handling which was done in a single large function.
Edited by Tuukka Lehtonen