When running as root (via `sudo su`, for instance), XDG_RUNTIME_DIR is
usually not set, which causes some warning messages to be printed prior
to screenfetch's output. I don't care about this, so I don't want to see
it.
In the interest of not messing with colons in filenames (among other
characters), this function has been changed to only remove control
characters and convert '/' to '-'. In the future, this should be updated
to check the current filesystem and use the appropriate munging for it.
Ref: https://stackoverflow.com/a/35352640/540162
Setting the `LESS` environment variable overrides the defaults used by
core.pager, which are FRX. Because `-R` is set in .bash_profile, only
`-FX` need be provided to provide the same option coverage.