Support ajaxified pagination of shortcodes with nested content

[bobbingwide]

v0.0.0-alpha.0316 supports an AJAX interface for paginated shortcodes which obtain their data from WordPress posts. This requirement is to support shortcodes which obtain their data from the shortcode content.

e.g.

[bw_csv posts_per_page=3]This,that
one,un
two,deux
...
ten,dix
[/bw_csv]

Proposed solution

Implement filter functions for "oik_shortcode_atts" and "oik_shortcode_content" ( new - see the related issue bobbingwide/oik/issues/22 ) to automatically paginate any content if the posts_per_page parameter is defined on the shortcode.

[bobbingwide]

Caveats

• The solution may not work for complex pages with multiple shortcodes with similar content
• The solution may not work for shortcodes in widgets

[bobbingwide]

While developing tests for oik-css I discovered a situation where the results of the test differs if oik-ajax is not activated. The filter function for the oik_shortcode_content filter shouldn't trim the content if the posts_per_page parameter is not set.