provide a means to remove a single data value that is an error

[rumachan]

If I upload data a subsequently discover there is an error with one data point (eg https://fits.geonet.org.nz/plot?sites=VO.RU001,VO.RU001A,VO.RU003,VO.RU004&typeID=t&days=30&type=scatter), the only way I have to remove that data point is to re-upload the complete data set with the --delete-first option. In some cases this is not very convenient, and being able to delete a single data value (for a given siteID, typeID, methodID) would be very useful.

[rumachan]

This is possibly better brought up as part of a wider discussion of how we manage the data in FITS. For GNSS this isn't an issue as all data are reloaded each day. But for volcano data (and landslide when they start to use FITS) there are many more small data sets and reloading is a lot more messy. Of course we should ensure we only load data without errors, but that isn't always possible when we are loading data from others who aren't doing that checking.