Provide detailed information about invalid titles

Provide detailed information about invalid titles

includes/Title.php
* The private method Title::secureAndSplit() now throws a
  MalformedTitleException instead of returning false on invalid
  titles.
* Added Title::newFromTextThrow(), which behaves exactly like
  Title::newFromText() but throws MalformedTitleException instead of
  returning null on invalid titles.

includes/title/MediaWikiTitleCodec.php
* Provide more information with the thrown MalformedTitleExceptions.

includes/MediaWiki.php
* Use the new Title::newFromTextThrow() to get detailed error
  information, display it.

Change-Id: I4da8ecb457a77473e32d745ba48ab8505b35e45f