Restore feature removed in c98dfef7: tap on title
to set dict of current result as a preferred dictionary
for this document.
Changes from former implementation:
- trust sdcv for ordering, instead of doing it ourselves
by looking at the results (which didn't always work)
- allow setting multiple preferred dicts
- order of preference is shown with a number as a prefix
to the dictionary name in the title
- taping again allows removing it from preferred dicts,
and taping again allows setting it back as the first
preferred dict