dat1New: Check status after locator is allocated
datAnnul: use new error context

Need to run even if status is bad.
datClone: Register early so that we can annul properly on error
datFind: Properly check and register
hdsNew: Check status after memory allocation
hdsOpen: Check status after memory allocation
hdstrack: Add defensive sanity check
hdstrack: Add routines for dumping locator and file registry