Add text to tab links telling if they do exist

Add text to tab links telling if they do exist

And changed a little bit signature of Linker::titleAttrib
and Linker::tooltipAndAcceskeyAttribs. Added $options
parameter to the second one and made $options parameter
satisfied by passing an array with options, because there
is one more now: 'nonexisting' which tells to add text
about the thing that the page does not exist to its tooltip.

Bug: T19099
Change-Id: Ia76dd6db363f6add5efb8955be9e23a1f8e8476f