Moved OTPayment and InstantiateContract into ext.
Moved out cash next to core.
Merge pull request #107 from murrekatt/develop

Finalized split-out of digital cash into own library
Moved OTMessageBuffer into client.
Moved out OTMessageOutbuffer to client.
Merge pull request #110 from murrekatt/develop

Moved buffers into client
OTPseudonym: replace OTCleanup with std::unique_ptr
OTPaymentPlan: replace OTCleanup with std::unique_ptr
OTTransaction: replace OTCleanup with std::unique_ptr
OTSymmetricKey: replace OTCleanup with std::unique_ptr