Added utility to create PDF tutorial from github wiki tutorial

I have written a bash script to generate a PDF of the tutorial from the github wiki. This means that in future we will only need to update the wiki tutorial rather than that and the PDF, thus making the wiki the home of all our updates.

The script does the following:
- Clones the wiki on to the local machine
- Amends some of the wiki files (removes the online navigation mainly, as this isnt needed in the PDF)
- Combines some of the pages to save space
- Creates pdfs of all the required wiki pages using gimli (software to convert markdown to pdf - installation instructions in the script)
- Combines these pdfs to create the manual (using pdftk - again instructions in the script)
- Cleans up removing all files used in the process

This script is in the utilities folder and will form part of the next release.

Kieran