Introduce 'spec' subdirectories to outline aspects

Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:

  repos/base/include/spec
  repos/base/mk/spec
  repos/base/lib/mk/spec
  repos/base/src/core/spec
  ...

Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.

Fix #1673

repos/libports/include/python/spec/x86_32/genode_defs.h

@@ -0,0 +1,20 @@
+/*
+ * \brief  Data type size definitions (32 Bit)
+ * \author Sebastian Sumpf
+ * \date   2010-02-17
+ */
+
+/*
+ * Copyright (C) 2010-2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _PYTHON__GENODE_DEFS_H_
+#define _PYTHON__GENODE_DEFS_H_
+
+#define GENODE_SIZEOF_LONG 4
+#define GENODE_SIZEOF_INT  4
+
+#endif /* _PYTHON__GENODE_DEFS_H_ */

repos/libports/include/python/spec/x86_64/genode_defs.h

@@ -0,0 +1,20 @@
+/*
+ * \brief  Data type size definitions (32 Bit)
+ * \author Sebastian Sumpf
+ * \date   2010-02-17
+ */
+
+/*
+ * Copyright (C) 2010-2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _PYTHON__GENODE_DEFS_H_
+#define _PYTHON__GENODE_DEFS_H_
+
+#define GENODE_SIZEOF_LONG 8
+#define GENODE_SIZEOF_INT  4
+
+#endif /* _PYTHON__GENODE_DEFS_H_ */