Fix warnings and enforce conventions in ContentHandler tests.

Fix warnings and enforce conventions in ContentHandler tests.

Syntax:
* Call parent setUp from setUp.
* Set required globals for the test inside the test class instead
  of assuming the default settings.
* Data providers are called statically and outside setUp/tearDown
  ("public static function")
* Test function names should be prefixed with "test"
  ("testIsRedirect")
* Marked 2 functions as unused. JavascriptContentTest has 2 data
  providers for tests that don't exist in it (nor in TextContentText)
  but do exist in WikitextContentTest.

Style:
* Single quotes
* Remove odd comment "# =====" lines
* Consistent tree wrapping with arrays.
  array(
      array(
          .. ) );
  array(
      array(
          ..
      )
  );
  Some were closing on the previous line instead.
  Made it consistent now.
* Remove odd indentation to make nested arrays line up:
  array( 'foo' => array(  'bar' => true,
                          'baz' => array() ) )
  array( 'foo' => array(
      'bar' => true,
      'baz' => array()
  ) )

  We don't do this kind of indentation because it is fragile
  and becomes outdates when any of the earlier keys ("foo")
  change. Converted to a regular tree instead.

  Also triggered git warnings for mixing spaces with tabs, which
  is almost always an detector for this style.

* Not using @annotations in inline comments, reserved (and only
  parsed/meaningful) for block comments.

Follows-up 8b568be5e2dfb889e1eeedbdca50b304864174f7

Change-Id: Ic55d539b9a58f448b550bcd98894d389764e0694