usfm2osis.py treatment of running headers (tag \h )

Knowing what a running header is intended for in Paratext, it seems quite inappropriate to just convert these to an ordinary title element.

Doing so merely adds to the clutter at the start of a book, and fails to fulfill the essential purpose of a running header.

It would be preferable to merely preserve the \h string as the value of an attribute for one of the main titles.

This is what one non-CrossWire OSIS converter does, namely Haiola.