Minor updates to README & example script
Added pyopengltk as a dependency (only required for VoidRender but it pip-installed no problem so I don't see any issues with it)
Also changed the VAST _version.py files to reflect the GNU-style major.minor.revision version numbers and put a note about that so hopefully we can be a bit more consistent
Minor updates to README & example script Added pyopengltk as a dependency (only required for VoidRender but it pip-installed no problem so I don't see any issues with it)