Unwanted updates

[fredj]

Tampermonkey on Google Chrome 28

To reproduce the issue:

• Select a .geojson file and click the Edit button
• Click the Map button
• Don't update anything
• Click the Preview button

All the geometries are marked as updated (by a very small value)

[tschaub]

Yes, this is annoying. We can fix this (by not updating the editor if we haven't gotten a featuremodified event). However, it is also a problem when making edits (see the rounding applied here on a delete).