setup: minor edits to add-ons
Porfile: added hdf5 variant
SegmentFormatter: kudgey fix for empty collections
Plot.add_colorbar: added cmap kwarg
SegmentPlot: remove print statement
TimeSeries.average_fft: fixed bug in data setting
Plot.show: added blocking support

    - uses pyplot.show if blocking=True
    - tries to guess whether to block by default based on __IPYTHON__
      and interactive_bk
lsctables: fixed docstring bug (sphinx)
examples: complete overhaul of examples

    - all examples rst is now automagically generated by ex2rst.py
    - examples separated into sub directories
    - example comments now parsed as RST, so I rewrote all the examples