OTContract: replace OTCleanup with std::unique_ptr
OTASCIIArmor: replace OTCleanup with std::unique_ptr
OTCachedKey: replace OTCleanup with std::unique_ptr
Merge pull request #115 from lclc/otcleanup2

OTContract, OTASCIIArmor, OTCachedKey: replace OTCleanup with std::unique_ptr
remove unused (for now) 'bitcoin-crypto' submodule
add crypto++ submodule and build
move to crypto++ zlib
move to crypto++ base64
replace openssl hash with cryptopp
ignore mac openssl deprecated-declarations
update travis to use system openssl on mac