shrink-backup.v1.0.0

I have made the decision to not deal with other partitions than boot and root for the 1.0 release.
Instead I introduced the --loop function to let the user expand the img file using the [extra space] option and then manually create partitions by running for example: sudo gparted /dev/loop0 in a terminal to edit partitions in a graphical interface using gparted.
I want to give the user freedom, but I also have to stay true to my initial plan with this script: a very fast utility to create a bootable img file from the system and subsequently keep it updated

I haven't dropped the idea of at least handling /home completely, but the script goes from "kinda basic functionality" to "advanced script" pretty fast when I start working on the feature.
If I do this, I still want the script to be as easy as possible to use, but at the same time give power users the ability to fine tune, ie a lot of work.

Features in the release:

• Introduction of --loop, --fix & -z (zoom speed)
• Now crosschecks fstab with lsblk for certain operations.
• Changed MB to MiB etc. Old habits die hard.
• Will now, if needed, check and/or ask for installing gdisk on debian and arch based systems.
• GPT partition table now supported
• Various bug fixes.