2018.7.15.1

Added file tracking to vasp_summary utilities.

Also: updates to murnfit script functionality:
2018-07-13:

• murnfit script now reads from unzipped vasprun.xml and gzipped vasprun.xml.gz files.
• murnfit script now takes -v, --verbose argument to produce a verbose output.
• murnfit script plots (using -p or --plot arguments) now use correct typography for axis labels (using matplotlib LaTeX support)