Sample output and visualisation in Blender

Blender file added for 3D visualisation of microtubule and
fluorophores. Sample output in the output directory is used by the
blender file to render a straight section of microtubule with a label
density of about 15%.

Visualisation should work for any output generated by
mt_profile_generate.m, as long as the names of the files are specified
correctly in the Blender python script. Run the script to visualise the
microtubule in Blender. Beware that microtubules larger than several
hundred nanometer may take a long time to read into Blender.