Reduce size of GET request to avoid HTTP 414

This will combine arrays from the GET request into CSV format to help reduce the size of data transferred via GET request which can cause HTTP 414 errors if too large. (EVE-Central appears to be limited to 2048 characters)

"URI length exceeds the configured limit of 2048 characters"

Example URL: http://api.eve-central.com/api/marketstat?typeid=34,35&regionlimit=10000002