Initialise environment from global Python variables

[jesper-friis]

Description

Alternative to PR #988 for fixing issue #978.

This PR allows Python application to configure dlite via global variables.

Global variables in (the __main__ module of) Python that starts with "DLITE_" will be set as environment variables seen by dlite.

Hence, starting your application as

DLITE_BEHAVIOR=ON python ./app.py

has the same effect as setting DLITE_BEHAVIOR="ON" before importing dlite in app.py.

Type of change

• Bug fix & code cleanup
• New feature
• Documentation update
• Test update

Checklist for the reviewer

This checklist should be used as a help for the reviewer.

• Is the change limited to one issue?
• Does this PR close the issue?
• Is the code easy to read and understand?
• Do all new feature have an accompanying new test?
• Has the documentation been updated as necessary?

[francescalb]

So do I understand correctly that with this change the warnings on bhaviour changes is remvoed by default when using dlite-validate? Can it be added if the users wants to? It would be good to write two sentences about this in the tools documentation (on dlite-validate)

[jesper-friis]

So do I understand correctly that with this change the warnings on bhaviour changes is remvoed by default when using dlite-validate? Can it be added if the users wants to? It would be good to write two sentences about this in the tools documentation (on dlite-validate)

Yes, the behavior warning is now removed in dlite-validate. It is possible to add a separate or extend the --debug option to turn on behavior warnings. In that case we have to process the options before importing dlite. Would you prefer that?

[francescalb]

So do I understand correctly that with this change the warnings on bhaviour changes is remvoed by default when using dlite-validate? Can it be added if the users wants to? It would be good to write two sentences about this in the tools documentation (on dlite-validate)

Yes, the behavior warning is now removed in dlite-validate. It is possible to add a separate or extend the --debug option to turn on behavior warnings. In that case we have to process the options before importing dlite. Would you prefer that?

I am not sure we need it. but if it easy do add witht he debug option it might be a good idea.

[jesper-friis]

So do I understand correctly that with this change the warnings on bhaviour changes is remvoed by default when using dlite-validate? Can it be added if the users wants to? It would be good to write two sentences about this in the tools documentation (on dlite-validate)

Yes, the behavior warning is now removed in dlite-validate. It is possible to add a separate or extend the --debug option to turn on behavior warnings. In that case we have to process the options before importing dlite. Would you prefer that?

I am not sure we need it. but if it easy do add witht he debug option it might be a good idea.

Done. Also made sure that needed cmake configurations are available in dlite-pyembed.c