A new wrinkle in gnx's:  The sax vnode code doesn't allocate gnx's unless necessary (the tnx attr doesn't exist).  This greatly reduces g.app.nodeIndices.lastIndex.
Fixed a few glitches in leoApp.py and leoAtFile.py discovered during testing.
Important: gnx's in @auto nodes *require* that timestamps are unique, which isn't necessarily so.  However, this is not likely the cause of bug #76.

Leo build: 20141021130234