WScript.LoadScriptFile search relative to the script location

[Cellule]

Right now, WScript.LoadScriptFile will search relative to the current working directory.
After the discussion in #244, I believe this was an oversight and this makes running test files without rl more difficult than it should be.
Unless someone as a valid use case to use current working directory, we should change it to use the current script's location.

[agarwal-sandeep]

@Cellule 3c743fd implemented this.

//cc @kfarnung @dilijev