Use python3-enforced explicit relative imports

Starting with Python 2.6 these are available without further redo.
In Python 2.5 you need the statement:

    from __future__ import absolute_import

For further information on Python2 v Python3 portability issues, see:

http://docs.python.org/3/howto/pyporting.html

Author: coldfix

pypandoc/__init__.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from pypandoc import convert
+from .pypandoc import convert
 
 __author__ = 'Juho Vepsäläinen'
 __version__ = '0.6.0'

pypandoc/test_pypandoc.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 import unittest
 import tempfile
-import pypandoc
+from . import pypandoc
 
 
 def test_converter(to, format=None, extra_args=()):