Exporting diagram to PDF

Easier to print :)
Names updated, exported to PNG

More organised and easier to load
Merge branch 'master' of https://github.com/criscmaia/BIS3214

# By Cristiano Maia
# Via Cristiano Maia
* 'master' of https://github.com/criscmaia/BIS3214:
  Names updated, exported to PNG
  Exporting diagram to PDF