trimfeedstart messed up feed, new data appears in future

[bluehawk]

I ran trimfeedstart on one of my feeds, and it worked well, it removed the old data I didn't want. Unfortunately, it seems like it messed up the feed, and now new data is being added in the future.

On Mar 7th, I trimmed the feed to start on Feb 17, removing about a month worth of messy data. That part worked, but now new data is showing up on Apr 8th, rather than Mar 8th. Note, it's not always one month of offset. I've tested other feeds, and the amount of "future offset" seems to be related to how much data was trimmed.

I think I've identified the problem (not updating npoints in the feed metadata after trimming the feed), and will be submitting a fix.