[Fedora-livecd-list] Update to liveimage-mount

[Frederick Grose]

I've submitted a pull request,
https://github.com/rhinstaller/livecd-tools/pull/9

for an update to liveimage-mount.

There are many integrated updates -- best reviewed by test driving.

Include a datetime tag to easily distinguish in-the-wild versions.
Provide infile utility and error-handling functions to permit standalone
    usage.
Provide option to skip error raising on subprocess calls.
Add support for live mounting a directory of LiveOS contents.
Add a /run/initramfs/livedev link and a /run/initramfs/live bind mount
    to simulate the LiveOS booted environment.
Add an option to mount filesystems read-only; and report the persistence
    status upon entering the command shell.
Create a non-existent mount directory, if needed, and remove it on exit.
Add support for DNF and/or Yum repository caches.
Use the /run tmpfs instead of /dev/shm.
Create non-persistent metadata type snapshot targets for in-memory
    overlays.
Use random device mapper & mount point names on successive invocations.
Support encrypted home filesystems.
Call programs by basename only, relying on $PATH searching.
Cleanup white space and line lengths.