HPselection per Fxp

Unlocks an hyperplanning page to allow selection. A first level of page modification unlocks selection in the main window. A second level of page modification can be used for popups selection. A third button is specific to the "list display": it makes it easy to select the whole list for copy and paste into a table (like libreoffice calc, Microsoft Excel or Google Spreadsheet).
Simply reload the page to cancel all the modifications.