Added: Setting for specifying which spellcheck dictionary is used.
Added: Setting for specifying which spellcheck dictionary is used.

Currently this is only used in the fixspaces code, but it potentially
be used elewhere.

ElvisResearchGroup/DictionaryOfNewZealandEnglish,ElvisResearchGroup/DictionaryOfNewZealandEnglish,ElvisResearchGroup/DictionaryOfNewZealandEnglish