Added EWF Image Support using libewf and pytsk3

Great presentation and tool for the Google Analytics Cookies! 

I remember that you had mentioned that it did not currently support EWF images. Using [libewf from Joachim Metz](https://code.google.com/p/libewf/wiki/pyewf), I was able to hand the data from the E01 images into the rest of the script as a raw image. 

I have tested and verified the data with single and split E01 files and tested and verified again with a raw image to ensure I didn't break anything in the steps.