wx Tasklist: fix bug
wx GUI: Improve comment
wx GUI: Remind bug #331
Remind bug #332
wx GUI: Remind bug #333
wx GUI: Remind bug #334
wx GUI: Remind bug #335
wx Scheduler: Remind bug #336
Reorganize keyboard shortcuts
Use a unified menu action and keyboard shortcut to close right-pane notebook tabs

Fixes #307
wx Tasklist: Add show panel action to tab context menu