Header guards according to convention.
Merge pull request #125 from murrekatt/include_guards

Header guards according to convention.
OTCachedKey: Replace tinythread mutex with std::mutex
OTLog: Replace tinythread mutex with std::mutex
OTSocket, OpenTransactions: Replace tinythread mutex with std::mutex
OTCrypto: Replace tinythread mutex with std::mutex
OTCachedKey: Replace tinythread with std::thread
OTCrypto: Replace tinythread with std::thread
Remove tinythread
Merge pull request #126 from lclc/tinythread

Remove Tinythread
remove unused '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