Timeseries, sort by _timestamp if no _start_at

When porting VisitorsRealtimeCollection to ListCollection I left in
data.reverse(). This was used to rearrange the data returned from
Backdrop into the correct order. Timeseries already tried to rearrange
the order of data based on _start_at, but realtime data about visitors
only has _timestamp. As ListCollection is now more generic, the job of
ordering should be the responsibility of Timeseries (probably should
have been before).

I have changed Timeseries to prioritise ordering on _start_at but if it
doesn't exist then fall back to _timestamp. Tests as proof!
ListView should use a ListCollection

We are sharing ListCollection with the VisitorsRealtimeView and it is an
extension of MatrixCollection. This means that we have to change how we
get the values out fo the Collection to the lovely
.first().get('values').
Add ListModule, some data and add to no-realistic

The data returned by preview at the moment looks a bit wierd by
illustrates the point.
Add an optional regex to extract label

We have some text we want to strip off from the labels we get back from
Backdrop. I have added a label-regex parameter to the module which gets
used in ListView. If it exists to will be converted to a RegExp object
and exec'd on the label, the first group in the regex will be extracted.