Moved netscript files into src folder and renamed

src/NetscriptEnvironment.js

@@ -0,0 +1,49 @@
+/* Environment
+ * 	NetScript program environment 
+ */
+function Environment(parent) {
+    this.vars = Object.create(parent ? parent.vars : null);
+    this.parent = parent;
+	this.stopFlag = false;
+}
+Environment.prototype = {
+	//Create a "subscope", which is a new new "sub-environment"
+	//The subscope is linked to this through its parent variable
+    extend: function() {
+        return new Environment(this);
+    },
+	
+	//Finds the scope where the variable with the given name is defined
+    lookup: function(name) {
+        var scope = this;
+        while (scope) {
+            if (Object.prototype.hasOwnProperty.call(scope.vars, name))
+                return scope;
+            scope = scope.parent;
+        }
+    },
+	
+	//Get the current value of a variable
+    get: function(name) {
+        if (name in this.vars)
+            return this.vars[name];
+        throw new Error("Undefined variable " + name);
+    },
+	
+	//Sets the value of a variable in any scope
+    set: function(name, value) {
+        var scope = this.lookup(name);
+        // let's not allow defining globals from a nested environment
+		//
+		// If scope is null (aka existing variable with name could not be found)
+		// and this is NOT the global scope, throw error
+        if (!scope && this.parent)
+            throw new Error("Undefined variable " + name);
+        return (scope || this).vars[name] = value;
+    },
+	
+	//Creates (or overwrites) a variable in the current scope
+    def: function(name, value) {
+        return this.vars[name] = value;
+    }	
+};