Bugfix - merging multiple data sources into single XML

Most of the xml templates requires single SQL query to fetch the data. Some more complicated templates, like Google Merchant Center, requires multiple sql queries. In these cases datakick engine run all queries and temporarily store results to a CSV files. After all queries has been executed it merges results into single XML.

Unfortunately there was a bug regarding new lines - if any data contained new line character, parsing CSV files would fail