cssvalue: Make border styles be their own value

... and add them via gtkcssenumvalue.[ch] which will be used for all
enums.

gtk/gtkcssenumvalueprivate.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright © 2012 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Alexander Larsson <alexl@gnome.org>
+ */
+
+#ifndef __GTK_CSS_ENUM_VALUE_PRIVATE_H__
+#define __GTK_CSS_ENUM_VALUE_PRIVATE_H__
+
+#include "gtkenums.h"
+#include "gtkcssparserprivate.h"
+#include "gtkcssvalueprivate.h"
+
+G_BEGIN_DECLS
+
+GtkCssValue *   _gtk_css_border_style_value_new       (GtkBorderStyle     border_style);
+GtkCssValue *   _gtk_css_border_style_value_try_parse (GtkCssParser      *parser);
+GtkBorderStyle  _gtk_css_border_style_value_get       (const GtkCssValue *value);
+
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_ENUM_VALUE_PRIVATE_H__ */