Check release mouse postion in CursorInvoker
Check release mouse postion in CursorInvoker

This affect when a palette will be opened, by example in the BuddyIcon
in the Sugar home.

sugarlabs/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3,i5o/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,sugarlabs/sugar-toolkit-gtk3,godiard/sugar-toolkit-gtk3,quozl/sugar-toolkit-gtk3,Daksh/sugar-toolkit-gtk3