Remove very old benchmarks that do not really work anymore are obsolet and rename "benches" to "benchmarks"

This is also going move the multi_bench benchmark into the benchmarks folder

benchmarks/diff_multi_bench_output.js

@@ -0,0 +1,92 @@
+#!/usr/bin/env node
+
+'use strict';
+
+/* jshint -W079: Ignore redefinitions (before & after) */
+
+var fs = require('fs'),
+    metrics = require('metrics'),
+
+    // `node diff_multi_bench_output.js before.txt after.txt`
+    before = process.argv[2],
+    after = process.argv[3];
+
+if (!before || !after) {
+    console.log('Please supply two file arguments:');
+    var n = __filename;
+    n = n.substring(n.lastIndexOf('/', n.length));
+    console.log('    ./' + n + ' multiBenchBefore.txt multiBenchAfter.txt');
+    console.log('To generate multiBenchBefore.txt, run');
+    console.log('    node multi_bench.js > multiBenchBefore.txt');
+    console.log('Thank you for benchmarking responsibly.');
+    return;
+}
+
+var before_lines = fs.readFileSync(before, 'utf8').split('\n'),
+    after_lines = fs.readFileSync(after, 'utf8').split('\n');
+
+console.log('Comparing before,', before.green, '(', before_lines.length,
+    'lines)', 'to after,', after.green, '(', after_lines.length, 'lines)');
+
+var total_ops = new metrics.Histogram.createUniformHistogram();
+
+function is_whitespace(s) {
+    return !!s.trim();
+}
+
+function parseInt10(s) {
+    return parseInt(s, 10);
+}
+
+// green if greater than 0, red otherwise
+function humanize_diff(num, unit) {
+    unit = unit || "";
+    if (num > 0) {
+        return ('+' + num + unit).green;
+    }
+    return ('' + num + unit).red;
+}
+
+function command_name(words) {
+    var line = words.join(' ');
+    return line.substr(0, line.indexOf(','));
+}
+
+before_lines.forEach(function(b, i) {
+    var a = after_lines[i];
+    if (!a || !b || !b.trim() || !a.trim()) {
+        // console.log('#ignored#', '>'+a+'<', '>'+b+'<');
+        return;
+    }
+
+    var b_words = b.split(' ').filter(is_whitespace);
+    var a_words = a.split(' ').filter(is_whitespace);
+
+    var ops =
+        [b_words, a_words]
+        .map(function(words) {
+            // console.log(words);
+            return parseInt10(words.slice(-2, -1));
+        }).filter(function(num) {
+            var isNaN = !num && num !== 0;
+            return !isNaN;
+        });
+    if (ops.length !== 2) return;
+
+    var delta = ops[1] - ops[0];
+    var pct = ((delta / ops[0]) * 100).toPrecision(3);
+
+    total_ops.update(delta);
+
+    delta = humanize_diff(delta);
+    pct = humanize_diff(pct, '%');
+    console.log(
+        // name of test
+        command_name(a_words) === command_name(b_words) ?
+            command_name(a_words) + ':' :
+            '404:',
+        // results of test
+        ops.join(' -> '), 'ops/sec (∆', delta, pct, ')');
+});
+
+console.log('Mean difference in ops/sec:', humanize_diff(total_ops.mean().toPrecision(6)));