rename underscore methods after the native [] method names, aliases for ruby versions

Even though the native methods have worse names (forEach, every, some),
since this library is trying to smooth over the native language it makes
more sense to use the native names, and provide aliases for more sensible
names from other languages, not the other way around.

Note this doesn't change any external usage, it just makes more sense.

This should also be useful for abstraction purposes for building underscore
functions, something like:

  addFn('some', {has_native: true, our_version: function () {...}})

this way we could feature detect on load for native versions and build a
function, and also have the option to turn off native versions for testing
our implementation.

I Also standardized the comments to look like:
  Delegates to JavaScript 1.x's native y if available.

underscore.js

@@ -44,8 +44,9 @@
 
   // The cornerstone, an each implementation.
   // Handles objects implementing forEach, arrays, and raw objects.
+  // Delegates to JavaScript 1.6's native forEach if available.
   var each = 
-  _.each = function(obj, iterator, context) {
+  _.forEach = function(obj, iterator, context) {
     var index = 0;
     try {
       if (obj.forEach) {
@@ -62,8 +63,8 @@
     return obj;
   };
 
-  // Return the results of applying the iterator to each element. Use JavaScript
-  // 1.6's version of map, if possible.
+  // Return the results of applying the iterator to each element. 
+  // Delegates to JavaScript 1.6's native map if available.
   _.map = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.map)) return obj.map(iterator, context);
     var results = [];
@@ -74,7 +75,8 @@
   };
 
   // Reduce builds up a single result from a list of values. Also known as
-  // inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
+  // inject, or foldl.
+  // Delegates to JavaScript 1.8's native reduce if available.
   _.reduce = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduce)) return obj.reduce(_.bind(iterator, context), memo);
     each(obj, function(value, index, list) {
@@ -84,7 +86,7 @@
   };
 
   // The right-associative version of reduce, also known as foldr. Uses
-  // JavaScript 1.8's version of reduceRight, if available.
+  // Delegates to JavaScript 1.8's native reduceRight if available.
   _.reduceRight = function(obj, memo, iterator, context) {
     if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
     var reversed = _.clone(_.toArray(obj)).reverse();
@@ -106,9 +108,9 @@
     return result;
   };
 
-  // Return all the elements that pass a truth test. Use JavaScript 1.6's
-  // filter(), if it exists.
-  _.select = function(obj, iterator, context) {
+  // Return all the elements that pass a truth test. 
+  // Delegates to JavaScript 1.6's native filter if available.
+  _.filter = function(obj, iterator, context) {
     if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
     var results = [];
     each(obj, function(value, index, list) {
@@ -126,9 +128,9 @@
     return results;
   };
 
-  // Determine whether all of the elements match a truth test. Delegate to
-  // JavaScript 1.6's every(), if it is present.
-  _.all = function(obj, iterator, context) {
+  // Determine whether all of the elements match a truth test. 
+  // Delegates to JavaScript 1.6's native every if available.
+  _.every = function(obj, iterator, context) {
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
     var result = true;
@@ -138,9 +140,9 @@
     return result;
   };
 
-  // Determine if at least one element in the object matches a truth test. Use
-  // JavaScript 1.6's some(), if it exists.
-  _.any = function(obj, iterator, context) {
+  // Determine if at least one element in the object matches a truth test.
+  // Delegates to JavaScript 1.6's native some if available.
+  _.some = function(obj, iterator, context) {
     iterator = iterator || _.identity;
     if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
     var result = false;
@@ -310,14 +312,15 @@
   // If the browser doesn't supply us with indexOf (I'm looking at you, MSIE),
   // we need this function. Return the position of the first occurence of an
   // item in an array, or -1 if the item is not included in the array.
+  // Delegates to JavaScript 1.8's native indexOf if available.
   _.indexOf = function(array, item) {
     if (array.indexOf) return array.indexOf(item);
     for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i;
     return -1;
   };
 
-  // Provide JavaScript 1.6's lastIndexOf, delegating to the native function,
-  // if possible.
+
+  // Delegates to JavaScript 1.6's native lastIndexOf if available.
   _.lastIndexOf = function(array, item) {
     if (array.lastIndexOf) return array.lastIndexOf(item);
     var i = array.length;
@@ -589,12 +592,12 @@
 
   // ------------------------------- Aliases ----------------------------------
 
-  _.forEach  = _.each;
+  _.each     = _.forEach;
   _.foldl    = _.inject       = _.reduce;
   _.foldr    = _.reduceRight;
-  _.filter   = _.select;
-  _.every    = _.all;
-  _.some     = _.any;
+  _.select   = _.filter;
+  _.all      = _.every;
+  _.any      = _.some;
   _.head     = _.first;
   _.tail     = _.rest;
   _.methods  = _.functions;