Ensure b-threads maintain their closures (if any), during analysis and execution

[michbarsinai]

e.g. here:

bp.registerBThread("closuredBThread", (function(e){
return function(){
    // using e as a variable
};
})(anEvent));

the object anEvent should be available to closuredBThread via variable e.

[geraw]

And e should be maintained as part of the b-thred's state in verification.