Add query parser encoding option

Hi, needed UTF-8 support and noticed that the bundle doesn't have an option to set ZendSearch QueryParser encoding, which was the only way i could get it to work properly. Tried a different analyzer but it didn't work, i had problems related to iconv. 
I've made some changes to your bundle to accept a new configuration parameter called query_parser_encoding to set the query parser encoding.

Great tool for those who need to use lucene by the way!!!
If we want to keep the bundle backward compatible, you should add it at last parameter of the method.