Changed wrong API reference in IElasticClient XMLDoc  and added page section to some API reference links
First attempt at adding .Fuzziness to suggest

- Changed the _Fuzzy property in CompletionSuggestDescriptor to
IFuzzySuggestDescriptor
- Updated FuzzySuggestDescriptor to implement IFuzzySuggestDescriptor
- Added FuzzinessSuggestDescriptor implementing IFuzzySuggestDescriptor
- Added .Fuzziness method to CompletionSuggestDescriptor
- Added unit tests in CompletionSuggestTests

Issues:
- Both the Fuzzy and Fuzziness methods returns a
CompletionSuggestDescriptor<T>, so that means you can chain .Fuzzy and
.Fuzziness. If you chain them, only the last one applied will be used.
That might not be a problem, depending on what level of knowledge is
expected from the developers using NEST.
Changed default behaviour of .Fuzziness

Now generates fuzzy: {} when not supplying anything to the .Fuzziness
method, as per
http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-completion.html#fuzzy
Fuzziness now generates empty JSON object by default

.Fuzziness() now generates:
```
"fuzzy": {
"fuzziness": {}
}
```

Updated tests to reflect this. Also cleaned up the expected strings in
some cases (and my auto format did sneak in some spaces to tabs
conversions, but it looks like that's the desired format, so I hope you
don't mind).

Also tried to add a page to the documentation about Suggest.
Cleaned up suggest documentation attempt.
Merge pull request #598 from andersosthus/master

Adding fuzzy on suggest