Unnecessary clutter in stdout

[rich-g]

The following messages are unconditionally printed to stdout when a thread is killed:

aws-iot-device-sdk-cpp/src/util/threading/ThreadTask.cpp

Line 35 in c20c9e9

std::cout << "Exiting Thread " << thread_descriptor_ << "!!" << std::endl;

aws-iot-device-sdk-cpp/src/util/threading/ThreadTask.cpp

Line 43 in c20c9e9

std::cout << "Successfully Exited Thread " << thread_descriptor_ << "!!" << std::endl;

This seems a bit odd, and it probably makes more sense for these to be AWS_LOG_DEBUG or AWS_LOG_TRACE messages instead.

[vareddy-zz]

Hi @rich-g ,
Yes, these would be better if they were AWS_LOG_DEBUG. I will push a fix to master after making the changes.
Thanks for the suggestion! They play an important role in improving the SDK.
Varun