Gstreamer 1.0: merge !13 into gstreamer_python_upgrade

Related to #56 (closed)

Note this change is built on !68 (merged). If you'd like to review this in isolation, check the last 2 commits.

I had to be more thorough on that one, since large changes were left off in the initial merge. I think large deletions or additions of full lines tend to either sneak in without causing merge conflicts, or they're changes which I accept without thinking. So I went through the original MR changes and my own, and made sure I had all the equivalent changes.

You can see the fixes in the most recent commit.

This catches up with the table column renames (and related changes). It doesn't include the fixes for background generation.

Test runs are here: /fred/oz996/tdavies/spiir_project/sources/testing/gout/py3/MR69_tests

The runs have the usual ND, and similar file sizes

There's one related change in the overall merge that I think I missed, which is removing future from a python file. I'll catch up on that and other optional changes in the final MR/merge.

New tests

The tests below weren't working at the time of this MR. For now we'll rely on Visual Inspections of the output. We'll followup when the script is working to make sure our outputs didn't regress throughout the merge process.

Daniel's created a test script that compares each row/column of two zerolag files. It tests at 2, 4, 8, and 12 significant digits, and currently all pass except for coaphase_V1 at 8 and 12 significant digits. You can find the results here:
/fred/oz016/tdavies/projects/tanghyd__spiir/test_zerolags/logs/test_zerolags_30656707.log