Make bodywidth kwarg overridable using config

[emillon]

Hey,

I believe I hit a problem with your library.

Default values for arguments are evaluated at import time.
This makes a problem when using html2text the following way:

import html2text  # The default value is evaluated here
html2text.config.BODY_WIDTH = 0
text = html2text.html2text(html)

It is thus necessary to wait until the function runs to fetch the actual
configuration value.

Thanks for maintaining html2text!

[emillon]

I'll add a test for this.

[theSage21]

@emillon Thanks for the fix. 😄

[Alir3z4]

@emillon Thanks for the patch, please fix the test suite and have a look at https://github.com/Alir3z4/html2text/blob/master/docs/contributing.md

Thanks for the great work.

[emillon]

There were no tests for the html2text.html2text function, so I added a third component to what generate_test returns. However, running it for the whole test suite does not work, because most options do not have a kwarg configuration. So I chose to run the "function" variant only for two tests, which adds enough coverage. Let me know what you think.