Auto Grab when click inside Remmina window
Problem to solve
When switching back and forth various windows or workspaces (e.g., in Ubuntu : Alt+Tab to swich windows, or Ctrl+Alt+Left/Right/Up/DownArrow to switch workspace), constantly, it's tedious to have to explicitly click on the GrabAllKeyboardEvents (or hit RightCtrl key) every time we come back to Remmina and want Alt+Tab or Fn keys or other special keys to work properly inside Remmina's remote session.
Further details
This problem does not exist for VirtualBox for instance, where focusing on the VirtualBox window will automatically grab all keyboard events (I think there's a parameter to activate/deactivate it in the GUI).
Proposal
Add an optional parameter in the GUI to have the GrabAllKeyboardEvents automatically activate whenever Remmina window is focused on or clicked into.