Changed wxGrid::OnPaint to call Refresh on subwindows.

Added Refresh to wxGrid::EndBatch().
Use batch mode in sample.
Changed CalcDimension to better handle cases with zero columns or rows.
No more automatic insertion of column when adding rows to a grid without
        columns.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_2_BRANCH@6947 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/newgrid/griddemo.cpp

@@ -497,11 +497,13 @@ void GridFrame::DeleteSelectedRows( wxCommandEvent& WXUNUSED(ev) )
 {
     if ( grid->IsSelection() )
     {
+        grid->BeginBatch();
         for ( int n = 0; n < grid->GetNumberRows(); )
             if ( grid->IsInSelection( n , 0 ) )
                 grid->DeleteRows( n, 1 );
 	    else
 	        n++;
+        grid->EndBatch();
     }
 }
 
@@ -510,11 +512,13 @@ void GridFrame::DeleteSelectedCols( wxCommandEvent& WXUNUSED(ev) )
 {
     if ( grid->IsSelection() )
     {
+        grid->BeginBatch();
         for ( int n = 0; n < grid->GetNumberCols(); )
             if ( grid->IsInSelection( 0 , n ) )
                 grid->DeleteCols( n, 1 );
 	    else
 	        n++;
+        grid->EndBatch();
     }
 }