Document Lucene queries in query_sb()

[lindsayplatt]

Lucene queries are available, though not correctly documented in ?query_sb - it's lq, not q. Also, lucene queries only work when a regular query is also defined, but it should work even if there isn't a q in the query_list.

Ex:

length(query_sb(query_list=list(lq='flood AND earthquake'), limit=100))
[1] 0
length(query_sb(query_list=list(q='', lq='flood AND earthquake'), limit=100))
[1] 62