New Features

getPageID() is now available, it returns the ID of a page.
{{NoBots}} will be checked by default, you can override this check with $OverrideNobots.
The function escape() is now available, to check SQL Strings against injections.
The function movePage() has now more parameters, it is more flexible.
[BREAKING CHANGE] getPageCats() uses now a different format to return results, see the docu for more details.
[BREAKING CHANGE] getLinks() returns now false if there are no links.

Bugfixes

private, protected, public are now used more meaningful.
editPageD() includes now the functionally of editPage() too.
The constructor was renamed, so you won't get a deprecation notice if you are using PHP7.

Variables were unified.
editPage and editSection functions are now performing actions using an internal function, this makes the code more clear.
The constructor of DBCore was renamed, since the old variant is deprecated since PHP7.
getCatMembers() is now public.
readPage() and other functions with the same functionality are now based on readPageEngine()
editPage() and other functions with the same functionality are now based on editPageEngine()
The legibility of the code was improved.
Viele API-Methoden wurden auf JSON umgestellt, die Fragen nun die API in JSON ab, konvertieren anschließend das Ergebnis in PHP, so das sich die weiterverarbeitung nicht ändert. Diese Umstellung wird von MediaWiki empfohlen.
A lot of API methods were changed from format=php to format=json. The functions will convert the result back, so you won't notice a change.