Control-parameters-step

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* Made the dialog larger

* Show all parameters

* Made appropriate comboboxes read only

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* Updated for the SEAMM argument parser moving to seamm_util

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* Added to the README text, and made it conform to the standard style

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Adds functionality to SEAMM for specifying key control parameters, items such as the
structure, temperature, and pressure, and use them as command-line parameters. In the
future, we will also provide the ability to set them when submitting a flowchart from
the Python or web interfaces.

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* First release on PyPI.