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
Merge pull request #108 from lclc/otpseudonymCleanup

OTPseudonym , OTPaymentPlan, OTTransaction, OTSymmetricKey: replace OTCleanup with std::unique_ptr