[cctbxbb] First svn commit

[James Stroud]

Hello All,

Since this is my first commit, I just want to make sure that I have done these things in the appropriate way.

Here's what I did:

1. Added a wiki page: https://sourceforge.net/p/cctbx/wiki/Subversion%20set%20up/
2. Added the method as_miller_arrays_map() to iotbx_mtz_ext.object, which is declared in iotbx/mtz/__init__.py.
3. Added a test for this functionality in the file iotbx/mtz/tst_miller_map.py

Please let me know if the manner in which I did anything could use improvement.

James