Merge pull request #9 from KhangPhucNguyen/master

#8: garbage-out should not depend on a stamp
Merge pull request #10 from KhangPhucNguyen/master

Done with ticket #1
should use file from the script's directory
no need for dot or stamp when the file is in the garbage
More like a README
use the delete option of find
Update README.md
good numbers
log things
treat symlink specially (just delete)
proper use of bc result
fix #15
stop on first error
fix #16