[libvoikko] Speller cleanup

[Harri Pitkänen]

I have done some cleanup in our spell checker code by removing some 
Finnish/Malaga specific tweaks from common spelling code path. This affects 
non-Finnish and experimental backends in such way that these tweaks are no 
longer applied to them.

The tweaks were such that they allowed certain words containing hyphens to be 
accepted even if the backend speller rejected them. From now on each backend 
must handle such things as appropriate for the language and implementation.

The default speller backend is now

  FinnishSpellerTweaksWrapper(AnalyzerToSpellerAdapter(currentAnalyzer),currentAnalyzer)

This means that the tweaks are still applied when default configuration is 
used. In case someone has set the previous default 
AnalyzerToSpellerAdapter(currentAnalyzer) explicitly in the configuration file 
and expects to still have these tweaks, please change your configuration.

Harri