Fix #306, and bin-file in $PATH make sense

[zhiyelee]

Almost revert #173 which lead to the bug in #306

Also remove deprecated customFds option in spawn

[zhiyelee]

@DigitalIO This PR is incompatible with #305 .

Indeed we can put the --harmony in the shebang

file: ~/bin/pm-list

#!/usr/bin/env node --harmony
"use strict";

let a = 5
console.log(5)

which works well with current PR:

✍ examples/pm list
5

How do u think about this? @DigitalIO @SomeKittens @thethomaseffect

[DigitalIO]

Adding --harmony to the shebang doesn't work in all environments, unfortunately. Some discussion. I've tried the example script on Debian (Stable) and Windows ("Git Bash") and it fails on both for me.

I have been initiating the scripts with node directly

> node --harmony examples/pm list

Not the best solution, but the best compromise I have found thus far.

[zhiyelee]

@DigitalIO windows will use this branch: https://github.com/tj/commander.js/pull/327/files#diff-168726dbe96b3ce427e7fedce31bb0bcR481
Your patch can be applied here.

Do u mean Debian don't support the --harmony option in the shebang?

#!/usr/bin/env node --harmony
"use strict";

let a = 5
console.log(5)

[DigitalIO]

Correct. env attempt to match "node --harmony" as a function, instead of "node" with the "--harmony" flag. It results in this error:

/usr/bin/env: node --harmony: No such file or directory

[zhiyelee]

@DigitalIO Seems there is a bug in Debian on the /usr/bin/env: node. nodejs/node-v0.x-archive#3911