[BUGFIX] Use title & alternative fields in filelinks

* The field "alternative" of the file should be used if filled.
* The field "title" of the reference should be preferred over the
  name if filled.

Resolves: #60429
Releases: 6.3, 6.2
Change-Id: I969dbb49a292f9980b9efa0e5e72ff2a9bc7e2f3
Reviewed-on: http://review.typo3.org/32748
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>