Merge pull request #4 in SITA/sita-paymentservicelib from feature/refactor to master
* commit '528020effd975d005da15b0b10866de4311aacee':
SITA-6 make payment processing thread safe
SITA-6 better error handling, async processing, and add comments
SITA-6 remove cocoapods and regenerate project file in advance of integration
SITA-6 more clean up
SITA-6 more name clean up and protocol abstraction
SITA-6 clena up naming and start abstracting into protocols
SITA-6 change to use XMLDictionary for XML parsing
SITA-6 change to use XMLDictionary for XML generation
SITA-6 add flight info serialization logic
SITA-6 add new transaction serialization class
SITA-6 fix copyright notices
SITA-6 Rename project to avoid namespace issues
