Scan functions inside of initializers or function calls

[OndrejSpanel]

Functions inside of initializers or function calls (and maybe in other positions as well) are currently ignored.

Such functions, passed as callbacks, are common is some JS enviroments.

First commit adds handling for functions defined in variable initializers, like this:

var f = function (s) {
  var something = s.compute()
};

I hope to be able to handle at least following scenario as well:

call(function (s) {
  var something = s.compute()
});

[OndrejSpanel]

I hope to be able to handle at least following scenario as well:

Should be done:

[OndrejSpanel]

A few more:

• function used in a return statement:

function (s) {
   return function (www) {
      var localInReturn;
   };
   
})(0);

• function in IIFE:

(function (x) {
   var localInIIFE;
   
})(0);

[OndrejSpanel]

I do not have intention working on this any further. I think even in current state it is an improvement and I suggest it to be merged as it is.

[bobbylight]

Thanks for the PR!