Improve wxQT cursor implementation, thanks @seandepagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77911 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Handle drawing lines correctly in wxQT, thanks @seandepagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77912 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix issues with dashes in wxQT, thanks @seandepagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77913 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775