Update buildCC.bat to check return codes

[sharwell]

Currently buildCC does not check return codes from the various calls to other scripts. This can lead to two problems:

1. If the code tools fail to build, the installer will still be created but it will use an old version of the code tools and Warnings and messages from static contract checking don't appear in the VS2015 error list #137 will reappear. The build logs must be manually inspected after each build to make sure it was successful.
2. In some cases, AppVeyor currently reports the build was successful even when it fails.

When one of the build scripts results in an error, the build should be stopped and the error code propagated back to the caller.