maint: Use convention "static_cast<void *>" for casting of pointers. * Backend.cc, BaseControl.cc, ButtonControl.cc, ButtonGroup.cc, Canvas.cc, Container.cc, ContextMenu.cc, Figure.cc, ListBoxControl.cc, Menu.cc, MouseModeActionGroup.cc, Object.cc, Object.h, Panel.cc, RadioButtonControl.cc, ToggleButtonControl.cc, ToolBar.cc, ToolBarButton.cc, annotation-dialog.cc, file-editor-tab.cc, main-window.cc, webinfo.cc, data.cc, ft-text-renderer.cc, graphics.in.h, zfstream.h, __init_fltk__.cc, __osmesa_print__.cc, gzip.cc, ov-java.cc, bp-table.cc, oct-time.cc, lo-utils.cc, oct-base64.cc, url-transfer.cc: Use convention "static_cast<void *>" for casting of pointers.

--- a/libinterp/dldfcn/gzip.cc	Thu Apr 27 09:48:57 2017 -0700
+++ b/libinterp/dldfcn/gzip.cc	Thu Apr 27 10:04:31 2017 -0700
@@ -267,7 +267,7 @@
       uchar_array (const std::string& str)
       {
         p = new Bytef[str.length () +1];
-        std::strcpy (reinterpret_cast<char*> (p), str.c_str ());
+        std::strcpy (reinterpret_cast<char *> (p), str.c_str ());
       }
 
       uchar_array (const uchar_array&) = delete;