add MinGW build guideline, add new version of Visual Studio
add MinGW build guideline, add new version of Visual Studio

bstarynk/jansson,bstarynk/jansson,Mephistophiles/jansson,markalanj/jansson,markalanj/jansson,markalanj/jansson,akheron/jansson,akheron/jansson,Mephistophiles/jansson,bstarynk/jansson,akheron/jansson