Use environment variable TYPEGUARD_DISABLE to disable typeguard.

[tage64]

Changes

Setting the environment variable TYPEGUARD_DISABLE disables Typeguard and has the same effect as running Python with the -O flag.

I wanted to compile my Python program with Nuitka which removes the source code so that the inspect module doesn't work. However, I did not want to disable all assertians with the -O flag.

Checklist

• You've added tests (in tests/) added which would fail without your patch
• You've updated the documentation (in docs/, in case of behavior changes or new
  features)
• You've added a new changelog entry (in docs/versionhistory.rst).

[coveralls]

coverage: 94.458% (-0.05%) from 94.511%
when pulling 859a611 on tage64:master
into b6a7e43 on agronholm:master.

[JohannesK71083]

@agronholm Why isn't this merged yet? Is there a problem/conflict/etc. with this PR?

[agronholm]

Because 1) I have plenty of other projects to maintain too, 2) I want to understand the feature and decide if I want it and if the it's the right approach.

[JohannesK71083]

Ok, I just wanted to know if there is any work to do to make this PR acceptable. Apparently not at this moment, thanks for the reply.