Oliver Rosoman

I tried running the example script linked in PR #344, and that failed with the following error:  I think this is to do with the timestamp being nested inside...

Ah yes it looks like it does indeed work when using the github version of the branch. I made some very minor changes on my local version which must have...

So TimeRange/s now inherits from Interval/s. I had to make a few changes to the latter classes due to a few edge cases not being accounted for - eg `interval.isdisjoint(interval)`...

Hopefully everything is now sorted - please have a peek when possible!