Added logger for dealing with issue #179

Added markdown files for the documentation.
parseError exposed from the mermaidAPI

src/logger.js

@@ -0,0 +1,94 @@
+/**
+ * #logger
+ * logger = require('logger').create()
+ * logger.info("blah")
+ * => [2011-3-3T20:24:4.810 info (5021)] blah
+ * logger.debug("boom")
+ * =>
+ * logger.level = Logger.levels.debug
+ * logger.debug(function() { return "booom" })
+ * => [2011-3-3T20:24:4.810 error (5021)] booom
+ */
+var Logger;
+
+Logger = (function() {
+    function Logger(options) {
+        var level, num, ref;
+        this.options = options || {};
+        this.level = this.options.level || Logger.levels.default;
+        ref = Logger.levels;
+        for (level in ref) {
+            num = ref[level];
+            Logger.define(this, level);
+        }
+    }
+
+    Logger.prototype.add = function(level, message, callback) {
+        if (this.level > (Logger.levels[level] || 5)) {
+            return;
+        }
+        if (callback) {
+            message = callback();
+        } else if (typeof message === 'function') {
+            message = message();
+        }
+        return this.write({
+            timestamp: new Date,
+            severity: level,
+            message: message,
+            pid: process.pid
+        });
+    };
+
+    function formatTime(timestamp){
+        var hh = timestamp.getUTCHours();
+        var mm = timestamp.getUTCMinutes();
+        var ss = timestamp.getSeconds();
+        var ms = timestamp.getMilliseconds();
+        // If you were building a timestamp instead of a duration, you would uncomment the following line to get 12-hour (not 24) time
+        // if (hh > 12) {hh = hh % 12;}
+        // These lines ensure you have two-digits
+        if (hh < 10) {hh = "0"+hh;}
+        if (mm < 10) {mm = "0"+mm;}
+        if (ss < 10) {ss = "0"+ss;}
+        if (ms < 100){ms = "0"+ms;}
+        if (ms < 10) {ms = "00"+ms;}
+        // This formats your string to HH:MM:SS
+        var t = hh+":"+mm+":"+ss +' ('+ms+')';
+        return t;
+    }
+
+    Logger.prototype.write = function(options) {
+        if(typeof console !== 'undefined'){
+            if(typeof log.debug  !== 'undefined'){
+                return log.debug(this.build_message(options));
+            }
+        }
+    };
+
+    Logger.prototype.build_message = function(options) {
+        return "[" + formatTime(options.timestamp) + "] " + options.message;
+    };
+
+    return Logger;
+
+})();
+
+Logger.define = function(logger, level) {
+    return logger[level] = function(message, callback) {
+        return this.add(level, message, callback);
+    };
+};
+
+Logger.levels = {
+    debug: 1,
+    info: 2,
+    warn: 3,
+    error: 4,
+    fatal: 5,
+    default:3
+};
+
+exports.create = function(type, options) {
+    return new Logger(options);
+};