Search doesn't match via altLabel if there is no prefLabel with the same language tag

[osma]

Copied from: https://code.google.com/p/onki-light/issues/detail?id=297

At which URL did you encounter the problem?
http://dev.finto.fi/asteri-cn/fi/search?lang=&q=tammerfors

What steps will reproduce the problem?

1. Search asteri-cn for "Tammerfors" in any language
   or
2. Search asteri-cn for "City of Tampere" in any language

What is the expected output? What do you see instead?

Expect to get the result "Tampereen kaupunki". Instead getting an error about no hits.

The concept only has a prefLabel with @fi language tag. The altLabels are "Tampere" (no lang tag) and "City of Tampere"@en. These are not matched because of this part in the SPARQL query:

&& langMatches(lang(?label), lang(?match))

which requires the matched label to have the same language tag as (one of) the prefLabel(s).

[osma]

Fixing this requires separating between UI language and search language in the Model code.

[osma]

Still affects the REST API, and therefore the autocomplete search. The problem is that as currently defined, the REST search method only takes one lang parameter. Another parameter should be added in order to separate between UI language and search language.