When copying files to the slaves the slave-setup-plugin misses directories that do not contain ordinary files.

The reason seems to be that the plugin uses the copyRecursiveTo method of the FilePath class to copy the files (Line 92 in SetupDeployer). The implementation of this method only acts upon files and then creates parent directories (Line 1895-1900 of FilePath). This results in creating only directories that contain directly or indirectly files.