Add URL and QueryString modules, and tests for each.

Also, make a slight change from original on url-module to put the
spacePattern into the function.  On closer inspection, it turns out that the
nonlocal-var cost is higher than the compiling-a-regexp cost.

Also, documentation.

lib/querystring.js

@@ -0,0 +1,177 @@
+// Query String Utilities
+
+var QueryString = exports;
+
+QueryString.unescape = function (str, decodeSpaces) {
+  return decodeURIComponent(decodeSpaces ? str.replace(/\+/g, " ") : str);
+};
+
+QueryString.escape = function (str) {
+  return encodeURIComponent(str);
+};
+
+
+var stack = [];
+/**
+ * <p>Converts an arbitrary value to a Query String representation.</p>
+ *
+ * <p>Objects with cyclical references will trigger an exception.</p>
+ *
+ * @method stringify
+ * @param obj {Variant} any arbitrary value to convert to query string
+ * @param sep {String} (optional) Character that should join param k=v pairs together. Default: "&"
+ * @param eq  {String} (optional) Character that should join keys to their values. Default: "="
+ * @param name {String} (optional) Name of the current key, for handling children recursively.
+ * @static
+ */
+QueryString.stringify = function (obj, sep, eq, name) {
+  sep = sep || "&";
+  eq = eq || "=";
+  if (isA(obj, null) || isA(obj, undefined) || typeof(obj) === 'function') {
+    return name ? encodeURIComponent(name) + eq : '';
+  }
+  
+  if (isBool(obj)) obj = +obj;
+  if (isNumber(obj) || isString(obj)) {
+    return encodeURIComponent(name) + eq + encodeURIComponent(obj);
+  }
+  if (isA(obj, [])) {
+    var s = [];
+    name = name+'[]';
+    for (var i = 0, l = obj.length; i < l; i ++) {
+      s.push( QueryString.stringify(obj[i], sep, eq, name) );
+    }
+    return s.join(sep);
+  }
+  // now we know it's an object.
+  
+  // Check for cyclical references in nested objects
+  for (var i = stack.length - 1; i >= 0; --i) if (stack[i] === obj) {
+    throw new Error("querystring.stringify. Cyclical reference");
+  }
+  
+  stack.push(obj);
+  
+  var s = [];
+  var begin = name ? name + '[' : '';
+  var end = name ? ']' : '';
+  for (var i in obj) if (obj.hasOwnProperty(i)) {
+    var n = begin + i + end;
+    s.push(QueryString.stringify(obj[i], sep, eq, n));
+  }
+  
+  stack.pop();
+  
+  s = s.join(sep);
+  if (!s && name) return name + "=";
+  return s;
+};
+
+QueryString.parseQuery = QueryString.parse = function (qs, sep, eq) {
+  return qs
+    .split(sep||"&")
+    .map(pieceParser(eq||"="))
+    .reduce(mergeParams);
+};
+
+// Parse a key=val string.
+// These can get pretty hairy
+// example flow:
+// parse(foo[bar][][bla]=baz)
+// return parse(foo[bar][][bla],"baz")
+// return parse(foo[bar][], {bla : "baz"})
+// return parse(foo[bar], [{bla:"baz"}])
+// return parse(foo, {bar:[{bla:"baz"}]})
+// return {foo:{bar:[{bla:"baz"}]}}
+var trimmerPattern = /^\s+|\s+$/g,
+  slicerPattern = /(.*)\[([^\]]*)\]$/;
+var pieceParser = function (eq) {
+  return function parsePiece (key, val) {
+    if (arguments.length !== 2) {
+      // key=val, called from the map/reduce
+       key = key.split(eq);
+      return parsePiece(
+        QueryString.unescape(key.shift(), true),
+        QueryString.unescape(key.join(eq), true)
+      );
+    }
+    key = key.replace(trimmerPattern, '');
+    if (isString(val)) {
+      val = val.replace(trimmerPattern, '');
+      // convert numerals to numbers
+      if (!isNaN(val)) {
+        var numVal = +val;
+        if (val === numVal.toString(10)) val = numVal;
+      }
+    }
+    var sliced = slicerPattern.exec(key);
+    if (!sliced) {
+      var ret = {};
+      if (key) ret[key] = val;
+      return ret;
+    }
+    // ["foo[][bar][][baz]", "foo[][bar][]", "baz"]
+    var tail = sliced[2], head = sliced[1];
+  
+    // array: key[]=val
+    if (!tail) return parsePiece(head, [val]);
+  
+    // obj: key[subkey]=val
+    var ret = {};
+    ret[tail] = val;
+    return parsePiece(head, ret);
+  };
+};
+
+// the reducer function that merges each query piece together into one set of params
+function mergeParams (params, addition) {
+  return (
+    // if it's uncontested, then just return the addition.
+    (!params) ? addition
+    // if the existing value is an array, then concat it.
+    : (isA(params, [])) ? params.concat(addition)
+    // if the existing value is not an array, and either are not objects, arrayify it.
+    : (!isA(params, {}) || !isA(addition, {})) ? [params].concat(addition)
+    // else merge them as objects, which is a little more complex
+    : mergeObjects(params, addition)
+  );
+};
+
+// Merge two *objects* together. If this is called, we've already ruled
+// out the simple cases, and need to do the for-in business.
+function mergeObjects (params, addition) {
+  for (var i in addition) if (i && addition.hasOwnProperty(i)) {
+    params[i] = mergeParams(params[i], addition[i]);
+  }
+  return params;
+};
+
+// duck typing
+function isA (thing, canon) {
+  return (
+    // truthiness. you can feel it in your gut.
+    (!thing === !canon)
+    // typeof is usually "object"
+    && typeof(thing) === typeof(canon)
+    // check the constructor
+    && Object.prototype.toString.call(thing) === Object.prototype.toString.call(canon)
+  );
+};
+function isBool (thing) {
+  return (
+    typeof(thing) === "boolean"
+    || isA(thing, new Boolean(thing))
+  );
+};
+function isNumber (thing) {
+  return (
+    typeof(thing) === "number"
+    || isA(thing, new Number(thing))
+  ) && isFinite(thing);
+};
+function isString (thing) {
+  return (
+    typeof(thing) === "string"
+    || isA(thing, new String(thing))
+  );
+};