This is just a refinement on how the word search is done in the dictionaries
that don't actually ability to search words in. Previously they emitted dummy
italicized suggestions, which were getting in the way. Now they don't emit
anything, but mark the search as uncertain. Any uncertain searches don't mark
the word input with the different color to indicate the search has failed.
Previously the program could only safely find two-word compounds. Now it always
finds all of them, even if they are large sentences with many words.
To choose the source for compounds, a notion of dictionary features was added.
It may be utilized later for some more interesting things.
