Load a tab only once

Dependencies

• [2] 4XVYHFDL Show an error message if tab loading fails
• [3] QCGCX2BR Generalize lazy tabs
• [4] YPDYBK5G Show dependencies as a tree rather than a list
• [5] BIVZGPUT Optimise clickable rows
• [*] IK53RV4V

Change contents

• edit in src/root/common.tt at line 461
  [3.407]

  [3.407]
  + var tabsLoaded = {};
• replacement in src/root/common.tt at line 465
  [3.542]→[3.542:580](∅→∅)
  − if (id == "#[% tabName %]") {
  [3.542]

  [2.0]
  + if (id == "#[% tabName %]" && !tabsLoaded[id]) {

  + tabsLoaded[id] = 1;