This optimization changes the search.Search.Next() interface API,
adding an optional, pre-allocated *DocumentMatch parameter.
When it's non-nil, the TermSearcher and TermQueryScorer will use that
pre-allocated *DocumentMatch, instead of allocating a brand new
DocumentMatch instance.
you can do a manual fuzzy term search using the FuzzyQuery struct
or, more suitable for most users the MatchQuery now supports
some fuzzy options. Here you can specify fuzziness and
prefix_length, to turn the underlying term search into a fuzzy
term search. This has the benefit that analysis is performed
on your input, just like the analyzed field, prior to computing
the fuzzy variants.
closes#82
