Utilize get_the_archive_title filter for series archive pages

[nerrad]

I recently became aware of the new function the_archive_title that was added for themes as a part of WordPress 4.1. I can use the corresponding get_the_archive_the_title filter to automatically setup the title for a series table of contents, or individual series archive page via this filter and themes using the_archive_title will integrate better with Organize Series out of the box.