[HUBZERO][#8089][LIB_HUBZERO] Make sure asset handlers can handle external assets
[HUBZERO][#8089][LIB_HUBZERO] Make sure asset handlers can handle external assets

zooley/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms