du: pick format for convert_size() once and reverse UNITS (again)

du: clean up block size parsing code

du: read block size environment variables

Allow build to fail on Redox

join: minor improvements and bug fixes

There was an issue with autoformat when the files had a different
number of columns in the first line. This commit fixes the issue and
extends the related test to cover this case.

Move the code to get the current key into a separate function.
Replace two 'combine' functions with one defined for Input.

Add license scan report and status

join: support headers

Signed-off-by: fossabot <badges@fossa.io>

[ls] Add "-1" Flag & Fix Needless Vec

blocksize env variables are read if -B is not specified as a command
line argument.
blocksize is now case insensitive (like gdu).

fn translate_to_pure_number() pulled out from existing code which
populated the block size variable

du -h: support GB

Allow -h (human readable form) to show sizes larger than MB
(This mimics original du behaviour)

Code refactored to remove duplication

README: remove incorrect information for Rust version

coreutils don't build on 1.20.0 anymore because `join` uses `?` for `Option`.

Fix Du mac/inodes

spelling
use POSIXLY_CORRECT and BLOCKSIZE env variables to determine block size.
move statics to const
use show_error! not show_info!

yes: use 16 KiB rather than 8 KiB for the buffer

Running du on mac gives different answers to linux. Hence our asserts
must differ for each platform

hard linked files are no longer counted - this mimcs the behaviour of
the original du.

du and other tools like stat assume a 512 byte block. ls is the only
tool to use 1024.

Add Simple set of tests

Port 'tail' to Redox

Port 'more' to Redox

Build chmod and install on Redox

Build 'test' and 'shred' on Redox