Bootstrap.bat: Add vs2019 support
Bootstrap.bat: Add vs2019 support

starkos/premake-core,dcourtois/premake-core,mandersan/premake-core,LORgames/premake-core,LORgames/premake-core,premake/premake-core,mandersan/premake-core,starkos/premake-core,starkos/premake-core,premake/premake-core,premake/premake-core,noresources/premake-core,mandersan/premake-core,dcourtois/premake-core,starkos/premake-core,dcourtois/premake-core,noresources/premake-core,LORgames/premake-core,premake/premake-core,premake/premake-core,dcourtois/premake-core,premake/premake-core,LORgames/premake-core,sleepingwit/premake-core,sleepingwit/premake-core,sleepingwit/premake-core,starkos/premake-core,noresources/premake-core,noresources/premake-core,mandersan/premake-core,noresources/premake-core,dcourtois/premake-core,noresources/premake-core,noresources/premake-core,LORgames/premake-core,dcourtois/premake-core,starkos/premake-core,sleepingwit/premake-core,premake/premake-core,mandersan/premake-core,sleepingwit/premake-core,starkos/premake-core,dcourtois/premake-core