symbols: provide minimal API to specify symbol directories

This gives us the ability to locate symbols by directory in a much more
maintainable manner. Library consumers can adjust their location based
on where they know symbols are likely to be located.

lib/sp-symbol-dirs.h

@@ -0,0 +1,33 @@
+/* sp-symbol-dirs.h
+ *
+ * Copyright (C) 2017 Christian Hergert <chergert@redhat.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef SP_SYMBOL_DIRS_H
+#define SP_SYMBOL_DIRS_H
+
+#include <glib.h>
+
+G_BEGIN_DECLS
+
+void    sp_symbol_dirs_add       (const gchar *dir);
+void    sp_symbol_dirs_remove    (const gchar *dir);
+gchar **sp_symbol_dirs_get_paths (const gchar *dir,
+                                  const gchar *name);
+
+G_END_DECLS
+
+#endif /* SP_SYMBOL_DIRS_H */