Change code to match the documented consensus formed on T321683:
https://www.mediawiki.org/wiki/Manual:Coding_conventions/PHP#Exception_handling
* Do not directly throw Exception, Error or MWException
* Document checked exceptions with @throws
* Do not document unchecked exceptions
For this extension, I think it makes sense to consider DOMException an
unchecked exception too (in addition to the usual LogicException and
RuntimeException).
Depends-On: Id07e301c3f20afa135e5469ee234a27354485652
Depends-On: I869af06896b9757af18488b916211c5a41a8c563
Depends-On: I42d9b7465d1406a22ef1b3f6d8de426c60c90e2c
Change-Id: Ic9d9efd031a87fa5a93143f714f0adb20f0dd956