Dvg-devices

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* Added device: Julabo circulator

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* Workaround for bug with unknown cause in ``Aim_TTi_PSU_protocol_RS232`` where
the power supply occasionally will skew the serial input and output stream,
such that the reply matches the second-previous query statement. Fixed by
forcefully flushing the serial input and output buffers whenever a wrong reply
is received. Hopefully, this will fix the skew when the next ``query()``
operation gets executed.

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* Fixed bug in ``BaseDevice.query_ascii()``. The use of ``ast.literal_eval`` got
removed because it chokes on ``nan``. Everything is now interpreted as a
``float`` instead.

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* Fix wrong import statement ``dvg-pyqt-controls``
* Fix wrong import statement ``dvg-pyqt-filelogger``

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* Added dependence ``dvg-pyqt-controls~=1.0``
* Added dependence ``dvg-pyqt-filelogger~=1.0``
* Added dependence ``dvg-pyqtgraph-threadsafe~=3.0``

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* Fixed bug in ``BaseDevice.py`` where ``inspect.getouterframes()`` would
momentarily suspend the thread. Solved by ditching inspect. The new
``ID_validation_query`` mechanism now relies on a simple boolean flag that
gets set to force ``query()`` to raise on timeout.
* Update dependence ``dvg-qdeviceio==0.3.0``