Add graphite2 integration from Martin Hosken

To be modified, a lot.

src/hb-graphite2.h

diff --git a/src/hb-graphite2.h b/src/hb-graphite2.h
new file mode 100644
index 0000000..0d471d5
--- /dev/null
+++ b/src/hb-graphite2.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2011  Martin Hosken
+ * Copyright (C) 2011  SIL International
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#ifndef HB_GRAPHITE2_H
+#define HB_GRAPHITE2_H
+
+#include "hb.h"
+#include "hb-shape.h"
+
+HB_BEGIN_DECLS
+
+
+#define HB_GRAPHITE_TAG_Silf HB_TAG('S','i','l','f')
+
+hb_bool_t hb_graphite_shape (hb_font_t    *font,
+			hb_buffer_t  *buffer,
+			const hb_feature_t *features,
+			unsigned int  num_features,
+            const char * const *shaper_options);
+
+int hb_graphite2_feature_check(const hb_feature_t *feats, unsigned int num_feats);
+
+HB_END_DECLS
+
+#endif /* HB_GRAPHITE2_H */