The intention of this pull is to be able to extend the existing unit-tests for payment requests. This is achieved by adding a second PaymentRequest Test CA (serial number f0:da:97:e4:38:d7:64:16) into paymentrequestdata.h. The CA was generated by my using "ca_in_a_box" (by @gavinandresen), which I've partly re-worked to natively run on Windows. Also the code in paymentservertests was reworked to be able to directly load payment request raw data from paymentrequestdata.h into an usable PaymentRequestPlus object. This is used to skip normal client code flow, to be able to explicitly test and verify payment request validity.
As a first step I integrated a new unit test, which is able to verify that the "client network matches the payment request network" rule is working as intended.