Pressbooks 3.9.8

Pressbooks 3.9.8 just went live on Pressbooks.com and all of our other production networks. Here’s what changed:

NOTICE: Pressbooks’ PHP version requirement (>= 5.6) and WordPress version requirement (>= 4.7.3) can no longer be overridden. Before installing Pressbooks 3.9.8, please ensure that your system has been upgraded accordingly.

• Feature: Themes can now be locked a particular version. The theme’s stylesheets and other assets will be copied into the book’s media directory and used for future exports (see #657, #704).
• Feature: The paragraph separation option is now available for webbooks (see #655, #696).
• Feature: The section openings PDF theme option now supports additional options (see #450, #691).
• Feature: When export sharing is enabled, the download links are now stable, e.g. /open/download?type=pdf (props to @rootl for the suggestion; see #684, #699).
• Enhancement: Pressbooks now supports third-party export formats (see #385 and #674).
• Enhancement: \Pressbooks\Options field display functions have been refactored to use an array of arguments instead of a list of parameters (see #648, #697) [BREAKING CHANGE].
• Enhancement: SCSS overrides have been moved into their respective theme options classes (see #452, #701).
• Enhancement: Webbook interface styles have been separated from the Luther book theme’s content styles (see #656, #708).
• Enhancement: Webbook stylesheet and script enqueuing has been clarified and simplified (see #396).
• Enhancement: Searching now excludes non-Pressbooks post types (props to @colomet for the report; see #706, #707).
• Enhancement: Front-end scripts are now loaded asynchronously (props to @bdolor; see #681).
• Enhancement: htmLawed is now a Composer dependency (see #702).
• Enhancement: The sassphp dependency is no longer required (see #693).
• Enhancement: The SaxonHE dependency check can now be overridden (see 7ea32fe).
• Enhancement: perchten/rmrdir is now used for recursive directory removal (see 37ab804).
• Enhancement: Added \Pressbooks\Utility\rcopy() function for recursive directory copying (props to @blobaugh for the example code; see 52b087b).
• Enhancement: Added pb_dependency_errors filter hook for suppression of dependency errors (see #719).
• Fix: Images on custom title pages are now exported as expected in EPUB and Kindle (see #690, #698).
• Fix: The diagnostics page now functions as expected on the root blog (props to @colomet for the report; see #688, #695);
• Fix: Print PDF exports are now available for download when export sharing is enabled (props to @bdolor; see #677).
• Fix: Numberless chapters no longer display a lonely period in PDF outputs from SCSS v2 themes (props to @thomasdumm for the report; see #670).
• Fix: Importing as a draft now works for EPUB imports (props to @thomasdumm for the report; see #668).