extract_corpora should take account of a custom.sty stylesheet when one is present in the project folder.

[davidbaines]

It looks like the extract_corpora code is ignoring the custom.sty stylesheet. Michael changed a custom.sty stylesheet so that certain custom markers would not be included in the extract file. No combination could be found that would exclude those notes.

When the custom.sty was renamed to usfm.sty this combination of settings ensured that the comments were excluded from the extract:

\StyleType Paragraph
\TextType Other
\TextProperties paragraph nonpublishable nonvernacular

[Enkidu93]

I think this is related to sillsdev/machine.py#204