anim_concentrations: make the movie generation actually work
dont -> don't
Export the number of diffusion events to writers
Fix writing of diffusion event statistics
Use testng and add some tests for array utilities
HDF5: split out "model" group

This should make it clearer what is a part of the
initial model, and what is a result of calculations.
HDF5: add titles and descriptions to all elements

In LAYOUTs, * means "rugged", i.e. the dimension varies and array
is filled with a dummy value to obtain rectangular array.
Remove unused variable
Also save stimulation event counts
HDF5: fix crash in jhdf5 with no targets
anim_concentrations: fix issue with backends
HDF5: fix ordering of axes in diffusion events
anim_concentrations: plot diffusion, use log norm
Remember reaction events per voxel, not just the sum
anim_concentrations: draw more than one thing at once
anim_concentrations: put all plots on one figure
Deterministic: arrays are 0 by default
HDF5, anim_concentrations: reaction tables
ReactionTable: simplify loop
anim_concentrations: display proper names of reactions