ExitOnError check error and exit if not nil.

FileExists check if a target exists and is a file.

FileIsExecutable file exists and is executable.

GetHomeDir get the user's homedir.

MkdirP err := utils.MkdirP("/lala", int(0755)) if err != nil { panic(err) }.

PanicOnError missing godoc.

PrintError if err is not nil print fmtstr as error.

PrintFatal missing godoc.