getCanonicalBasepublic static String getCanonicalBase
(ServletContext servletContext, HttpServletRequest request, Book book)Gets the canonical base URL, not including any trailing slash, such as
https://example.comThis is configured in the book via the "canonicalBase" setting.
TODO: Create central per-request warnings list that could be reported during development mode, include this warning on requests. TODO: Also could use that for broken link detection instead of throwing exceptions.