Fix a bug which cause scripts on command line run out of order

[alexzhuustc]

There is a code processes path in parallel mode which MAY cause run scripts out of order.

e.g. nodeunit a.js b.js c.js d.js the execute order may looks like -> b.js -> c.js -> a.js -> d.js

I believe it's not an intended design, as all other codes are carefully handle path in series mode.

[Sannis]

+1 on this.

[KishCom]

Are there plans to integrate this soon?

[Emeraude]

4 years later, why is this PR unmerged ? It fix an error that occur very often and that can be very annoying, depending on your use case.