Add new style for JITE

... JITE = Journal of Institutional and Theoretical Economics.

 * English style by German publisher
 * This style looks quite similar to the Chicago Manuals Style, but they don't mention anything in their style guide.
 * Update finanzarchiv.csl: Add pages in chapter/inproceeding (forgot before #1115)
Since it looks like that ISSN is still used in some catalogs, I don't see any harm in keeping it.