K 10
svn:author
V 3
jhb
K 8
svn:date
V 27
2014-09-30T17:19:07.241717Z
K 7
svn:log
V 217
Explicitly return None for negative event indices.  Prior to this,
eventat(-1) would return the next-to-last event causing the back button
to cycle back to the end of an event source instead of stopping at the
start.

END