Fixed encoding issues in xml2sql.py script.
Changes in xml2sql script SQL generation.

Change: The XML elements are now merged in one common python dictionary.
Change: Both en and bg XML data is now outputed to one single SQL file.
Add: Output file parameter to xml2sql script (-out). Default file name is
'xml.sql'.
No INSERT queries for added additives
Updated UTF-8 encoding of XML files
Unified additive properties SQL generation.