issue #19800: refinements to the hiding of site
issue #19800: move hiding logic to the site picker itself
issue #19800: clean up diff
issue #19800: better implementation
Merge remote-tracking branch 'XTUPLE/master' into 19800
issue #19800: use inherited arguments correctly
issue #19800: don't assume session is there yet
Merge pull request #594 from shackbarth/19800

issue #19800: refinements to the hiding of site