Update Examples: new time series notebook, plus more cleanups

[emiliom]

• Added TimeSeries_RetrieveVisualize.ipynb, based originally (way back) on Sample.py and more recently on the entry in the BiG-CZ notebook gallery. Added corresponding SQLite ODM2 database
• Removed Sample.py, as it's no longer of use (and was very old)

[emiliom]

Addresses #157 and is a follow up to #160. As with that PR, this PR only involves files in the Examples folder, not the code base per se. I'm merging into master branch so the updates are immediately accessible. Also, I'm self merging, since it only involves Examples (ie, its impact is limited).