relax SVN archive

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.

Python 3 integer division to float fix for the frame order analysis.

Python 3 bug fix for the frame order analysis - another int division problem.