Plastic surgery
Unfinished prototype for stereo calibration
Expand calibration class

Now I actually can produce calibration matrices. This is as yet untested.
Finish calibration

Calibration is now an object of its own that can export and import itself from
other calibrations and from disc, implemented in the class
``CameraCalibration``.

The ``StereoCalibrator`` class is now finished as well.
Make main function for calibrate_stereo.py

Now you can use the classes as a command line tool.
Rename CameraCalibration to StereoCalibration
Let StereoCalibration rectify stereo image pairs

Also update the documentation a bit.
Add tool to tune block matching algorithm
Report chosen parameters to user

This allows the user to just set what seems right for the stereo block matcher
and then look at the end and see what worked the best.
Add possibility to save BM settings

This is also integrated into the GUI.
Add possibility to show camera views while getting chessboards
Rework UI to show progress and live camera images while finding chessboards
Have webcams destroy windows they own when exited

Before, webcams did not manage their own windows, so although they released
their cameras on exit, the windows remained open to be closed manually. This is
no longer the case.
Extract calibration into top-level function

This enables the calibration function to be called from other files as well, so
that I can add the option of live calibration to ``chessboard_photos.py``. The
function is also called from ``main`` in ``calibrate_stereo.py``, so it's
unredundant.
Move argparse parent to ``calibrate_stereo.py``

I am planning on using ``calibrate_folder`` in ``chessboard_photos.py`` and
want to avoid a circular import.
Allow user to calibrate stereo pair live

This is done by using ``calibrate_folder`` from ``calibrate_stereo.py``.
StereoCalibration creates export folder if neeeded

This makes a ``StereoCalibration`` behave more robustly: If you ask it to
export itself to a nonexistent folder, it creates the folder. Previously, this
led to an exception.
Cleanup chessboard_photos.py's UI

If a user specifies a calibration folder, he obviously wants to calibrate.
Therefore there was no purpose in forcing the user to use the calibration flag
when he wanted to calibrate. Now that option has been removed, simplifying the
UI. Also, unused imports were cleaned up.
Adjust available StereoBM settings

Previously, only very conservative settings were allowed, and the GUI did not
restrict these settings dynamically. Now a bit of redundancy has been removed -
the GUI looks at what the maximum settings are, and they're stored on the class
themselves, rather than using the same literal twice in the same file.
Normalize disparity map in GUI

This makes it a lot easier to tune the StereoBM.