The zero-padding used to identify the PART and END headers is not part
of the header itself but rather padding from previous data structures.
That is totally fine since the padding will always be there when
analyzing Ubiquiti firmware images.

Add support for extracing into subdirectories named by the offset.

1.deps.sh now checks distro version number and displays it

2.Seperate dependencies now used for ubuntu 17
	- cramfsprogs is not in default repos for 17

Added fake entropy graph plot at offset 0 to ensure a full graph even if the entire file has high entropy

Updated unpfs extractor to create unique output directories in the event of multiple PFS images inside the same file; added directory traversal check.