relax SVN archive

Another Python 3 fix for the relax_io.extract_data() function.

Sometimes this function sees byte types, sometimes string types. The function can now handle both.

The Mf.test_write_results system test can now select the correct file to compare against in Python 3.

The algorithm for determining if the 'final_results_trunc_1.3_v2' or
'final_results_trunc_1.3_pre_py2.7.3_v2' file should be used could not handle Python 3.

The relax_io.DummyFileObject now mimics a file object for both Python 2 and 3.

In Python 3, everything from a file is of byte type and no longer string type.

Python 2 fix for the relax_io.extract_data() function for a bug introduced at r17669.

Python 3 fix for the format detection of results and save files.

Python 3 import fixes for the generic_fns.structure package using relative paths.

Python 3 fix for the writing out of XML formatted state and results files.

In Python 3, the xmldoc.toprettyxml() returns a string object which needs to be 'encoded' prior to
writing out to file.

Python 3 fix - removed the use of the string.lower() function in the OpenDX mapping code.

Python 3 fix for the frame order system tests matching r17678.

As float to string conversions behave differently, the %.1f formatting is used to force only a
single decimal place float.

Python 3 fix for the frame order system tests - float to string conversions behave differently.

Now the explicit %.1f formatting is used to force only a single decimal place float.