start mqtt client (based on paho.mqtt.c), basically works

3rd/paho.mqtt.c/cbuild.bat

@@ -0,0 +1,24 @@
+REM start broker and proxy
+REM Start-Process C:\Python36\python -ArgumentList 'test\mqttsas.py'
+REM Start-Process C:\Python36\python -ArgumentList 'startbroker.py -c localhost_testing.conf'
+
+setlocal
+set APPVEYOR_BUILD_FOLDER=%cd%
+
+rmdir /s /q build.paho
+mkdir build.paho
+
+cd build.paho
+
+REM call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x64
+call "j:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
+
+cmake -G "NMake Makefiles" -DPAHO_WITH_SSL=TRUE -DPAHO_BUILD_DOCUMENTATION=FALSE -DPAHO_BUILD_SAMPLES=TRUE -DCMAKE_BUILD_TYPE=Release -DCMAKE_VERBOSE_MAKEFILE=TRUE ..
+
+nmake
+
+ctest -T test -VV
+
+cd ..
+
+endlocal