Make C++ alarm class usable and testable - there were some build issues and

BUILD

Makefile

build.yaml

include/grpc++/alarm.h

test/cpp/common/alarm_cpp_test.cc

tools/doxygen/Doxyfile.c++.internal

tools/run_tests/sources_and_headers.json

tools/run_tests/tests.json

vsprojects/vcxproj/grpc++/grpc++.vcxproj

vsprojects/vcxproj/grpc++/grpc++.vcxproj.filters

vsprojects/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj

...s/vcxproj/grpc++_unsecure/grpc++_unsecure.vcxproj.filters

...ojects/vcxproj/test/alarm_cpp_test/alarm_cpp_test.vcxproj

...cxproj/test/alarm_cpp_test/alarm_cpp_test.vcxproj.filters