D365 FO and External DLLs

We recently had to add some external dlls to our D365 for Finance and Operations model.  We found out that when the references are added to a project, an XML descriptor of the reference is placed in $\LCS Dynamics Ax\Trunk\<your branch>\Metadata\<your model>\<your model>\AxReference.  However, once you ready to deploy, the actual dll must be manually added to $\LCS Dynamics Ax\Trunk\<your branch>\Metadata\Bin.  Otherwise, the LCS build will fail with a class not found error.