Bugfix: internal pages were not processing language after redesign and use fix paths...

Bugfix: internal pages were not processing language after redesign and use fix paths output handling

When I wrote the language handling into the initial setting load function and then changed the output handling to be more dynamic, I forgot to update p_include_path().
Get rid of the loop when deciding the language include file suffix and only use the last entry in the aliases array (generally the shortest).
There were some cases where I was still using $this->html instead of $this->content.
Be more consistent by using $this->output instead of $this->content.