Errors go to os.Stderr now.
Gofmt sleep/main.go
Add Mv Implementation
Fixes for Mv implementation
Mv is good enough now: implement -t flag

Fuck the rest of the GNU extensions to mv
Use defer to keep going but exit with error code
Wow goopt.Args exists. Also, minor bug in rm
Print out help message if lacking arguments
Simplify Mv since it uses goopt.Args now