Update pybuffer.i library to use new-style Python buffer C API.

Removed old API altogether as Python 2.7 is now the minimum version
supported and it supports the new-style buffer API.

Examples/test-suite/python_pybuf.i

@@ -1,6 +1,6 @@
 %module python_pybuf
-%include<pybuffer.i>
-%include<cstring.i>
+%include <pybuffer.i>
+%include <cstring.i>
 /*functions for the test case*/
 %pybuffer_mutable_binary(char *buf1, int len);
 %pybuffer_mutable_string(char *buf2);