CMake: don't treat warnings as errors in otprotob

The code is auto-generated by Google Protobuf.
opentxs: fix -Wunused-macros
Merge pull request #294 from toxeus/removeUnusedMacros

opentxs: fix -Wunused-macros
OTPaths: fix -Wundef
Merge pull request #296 from toxeus/fixUndef

OTPaths: fix -Wundef
git: append newline to pre-commit hook's error report
Merge pull request #297 from toxeus/fixGitHook

git: append newline to pre-commit hook's error report
Removed OTDataCheck.
Merge pull request #298 from benma/unusedFuncs

Removed OTDataCheck.
Make includes consistent: Google C++ style guide, no "../", etc.
cppcheck: update include folder.
clangformat on OTSignature.hpp.
Merge pull request #293 from benma/cleanup

Made all includes consistent
Removed OTPseudonym::CertfileExists.
Removed OTClient::ConnectToTheFirstServerOnList.
Removed OTString::ConvertToLowerCase.
Removed OTIdentifier::CopyTo.
Removed OTCrypto::DeriveKey and cleaned up comments.
Removed OTEnvelope::(Get|Set)AsBookendedString.
Removed OTSocket::GetBindingPath, GetConnectPath.