https://github.com/bootandy/dust/issues/92
Not 100% sure if this code is clean yet, may well be a better way to do
it
Also:
Added test directory with incredably long name as test case.
Update test_symlinks.py for mac runners. Mac test runners create files
with very long names, hence the tests fail periodically unless they look
for a truncated name with '..' at the end.
Use the whole width of the terminal assume width of 80 if none found
Show percentages in the final column. Show ASCII bars indicating usage
of the underlying directories in the space inbetween.
Display (height of terminal - 10) entries by default.
Reverse the output order so largest is at the bottom.
Break up tests. Change older tests to check real output of program.