first step of the big refactoring ("tree" branch).

From here on, we can track changes. It made no sense to put the
development up to this point into git.

include/x.h

@@ -0,0 +1,15 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ */
+
+#ifndef _X_H
+#define _X_H
+
+void x_con_init(Con *con);
+void x_con_kill(Con *con);
+void x_window_kill(xcb_window_t window);
+void x_draw_decoration(Con *con);
+void x_push_changes(Con *con);
+void x_raise_con(Con *con);
+
+#endif