Add a Feature to core CP add_shortcode to deal with unwanted wpautop

[viktor]

There was a good petition for redoing shortcode parser. This could be tied into that.

Rewrite the shortcode parser to support nested shortcodes and self-nested shortcodes

The current shortcode parser is based on a single regular expression, making it error-prone and incapable of many useful features, such as nesting two instances of the same shortcode. Here is a proof of concept parser for shortcodes that supports nesting and self-nesting out of the box: https://github.com/gschoppe/Better-Shortcode-Parser Read-only archive: https://petitions.classicpress.net/posts/146/rewrite-the-shortcode-parser-to-support-nested-shortcodes-and-self-nested-shortcodes Author:…