Added methods to get/set the pen width used for the current cell highlight, bot normal and read-only. Fixed (I think) the problem of the cell highlight leaving extra lines behind when the grid lines are turned off git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10092 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775