Add regression tests for bad h5 data neurite trunk issue.
Add regression tests for bad h5 data neurite trunk issue.

2nd point of neurite initialsections had Z coordinate corrupted
in h5 files translated from previously invalid Neuron.swc. This
has been fixed, but had no specific test.

Note: the new h5 file is still incorrect, in that it has more than 1
soma section. This seems to be an artefact of the Brion translation.
See https://github.com/BlueBrain/Brion/issues/90.

Resolves #480.

eleftherioszisis/NeuroM,BlueBrain/NeuroM,lidakanari/NeuroM,mgeplf/NeuroM,liesbethvanherpe/NeuroM,wizmer/NeuroM,juanchopanza/NeuroM