build.bat will build the entire solution set one by one, which is single
threaded. On multi-processor builders in a CI/CD system, this is a bit
sluggish.
Enable msbuild -maxCpuCount on all msbuild commands, which will parallelize
msbuild actions where possible.
On an Azure Standard_DS2_v2 (i.e. a 2 vcpu builder) this change reduces
build_AllNoSdv.bat time from 12 min to 8 min.
Also, fix minor nit in top of file comments to reflect supported build targets,
which removes Win7, adds Win8.1.
Signed-off-by: Jon Kohler <[email protected]>