Send error data via temp file

Add ability to send data to the Raygun API using a file instead of a data string. The original method failed when data that needed to be escaped was not escaped properly. Rather then add regex's to add the proper escaping a temp file is used to store the data to be sent. Since the sending is done asynchronously this should have minimal impact on the performance other than writing to the temp file however it provides the flexibility for end users to just pass in their data without having to worry about properly escaping the data.