Software update

I've been running a local version of emoncms for about 8 months now, I'm using a Raspberry Pi base station with everything being written to a USB HDD, an emonTX v2 and a low power emonTH (without the humidity sensor), apart from the time when the partition on the HDD filled up and everything stopped working and a recent episode where for no apparent reason the gLCD stopped receiving updates (now fixed itself), the system has been pretty stable and reliable.

I'd like to update to the latest version of the software to try out some of the newer features described, is there an upgrade path for me or do I have to start again from scratch? Ideally I'd like to keep the 8 months of feed data I currently have.

Regards, Keith