[Feature request] Create a tray icon on runtime

[woubuc]

Is your feature request related to a problem? Please describe.
I would like to be able to create a tray icon during runtime.

Use case: an application that shows a login window on startup, and only after login are the main window and the tray icon created.

Describe the solution you'd like
A way to create/remove tray icons on runtime. Or at least a way to toggle the tray icon so it can be hidden on startup and shown again later.