Skip irrelevant initial empty pages when displaying a text.

[Philip Burns]

No description provided.

[Craig Berry]

Resolved by:

commit a307944acedd2e6f3b28d41bf30056e12fa22920
Author: Craig A. Berry <[e-mail]>
Date:   Sun Apr 23 21:32:19 2017 -0500

    Don't display blank pages.

    There are a lot of blank pagse in the TCP documents, and it's
    annoying to have to navigate through them.  We now mark these as

      <pb type="blank">

    in the XML documents, so when looking for next or previous page,
    look for the next or previous non-blank page by excluding those
    with this type attribute.

[Martin Mueller]

Big improvement!