added Filter Factory supporting loading tokenizer using reflection

Added support loading Tokenizers using reflection. E.G. loading NorwegianMinimalStemFilter : 
{
    "settings": {
        "analysis": {
            "filter": {
                "my_stemmer": {
                    "type": "class_token_filter",
                    "class": "org.apache.lucene.analysis.no.NorwegianMinimalStemFilter"
                }
            },
            "analyzer": {
                "default": {
                    "filter": ["standard", "lowercase", "my_stemmer"],
                    "tokenizer": "standard"
                }
            }
        }
    }
}