Logger with debug level; and this becomes a no-op when compile in optimized mode
Enable verbose logging
Convert debug to llvm raw ostream
Merge pull request #194 from lqi/logger

Enable logging for debugging and verbose information
Catch up with latest clang API changes
Hold FeatureEnvy rule from shipping until we have a better understanding
temporary fix for gmock r477 by updating gtest to the latest r686
Use std::error_code to replace llvm::error_code
Update for llvm api changes
Link the latest Rewrite lib
Catch up with latest llvm changes
Updates regarding unique_ptrify JobList::Jobs