[3.4] Neuer Alias string & Relative URLs für Links A/B/C in com_content

Siehe:
https://github.com/joomla/joomla-cms/commit/0b0096c4efcb4dc6e8ebf1b96260a4f047f365dd
und
https://github.com/joomla/joomla-cms/commit/e8ff0f756341f2855be6d0a9e284a2ce63e2cbbb