fixes #1376 adding documentation to draw

Author: Lauren McCarthy

src/core/core.js

@@ -121,6 +121,13 @@ var p5 = function(sketch, node, sync) {
    * exist if you want the code to run continuously, or to process events such
    * as mousePressed(). Sometimes, you might have an empty call to draw() in
    * your program, as shown in the above example.
+   * <br><br>
+   * It is important to note that the drawing coordinate system will be reset
+   * at the beginning of each draw() call. If any transformations are performed
+   * within draw() (ex: scale, rotate, translate, their effects will be
+   * undone at the beginning of draw(), so transformations will not accumulate
+   * over time. On the other hand, styling applied (ex: fill, stroke, etc) will
+   * remain in effect.
    *
    * @method draw
    * @example

src/io/p5.XML.js

@@ -8,7 +8,48 @@
 
 var p5 = require('../core/core');
 
-
+/**
+ * XML is a representation of an XML object, able to parse XML code. Use
+ * loadXML() to load external XML files and create XML objects.
+ *
+ * @class p5.XML
+ * @constructor
+ * @return {p5.XML}    p5.XML object generated
+ * @example
+ * <div class='norender'><code>
+ * // The following short XML file called "mammals.xml" is parsed
+ * // in the code below.
+ * //
+ * // <?xml version="1.0"?>
+ * // &lt;mammals&gt;
+ * //   &lt;animal id="0" species="Capra hircus">Goat&lt;/animal&gt;
+ * //   &lt;animal id="1" species="Panthera pardus">Leopard&lt;/animal&gt;
+ * //   &lt;animal id="2" species="Equus zebra">Zebra&lt;/animal&gt;
+ * // &lt;/mammals&gt;
+ *
+ * var xml;
+ *
+ * function preload() {
+ *   xml = loadXML("assets/mammals.xml");
+ * }
+ *
+ * function setup() {
+ *   var children = xml.getChildren("animal");
+ *
+ *   for (var i = 0; i < children.length; i++) {
+ *     var id = children[i].getNumber("id");
+ *     var coloring = children[i].getString("species");
+ *     var name = children[i].getContent();
+ *     print(id + ", " + coloring + ", " + name);
+ *   }
+ * }
+ *
+ * // Sketch prints:
+ * // 0, Capra hircus, Goat
+ * // 1, Panthera pardus, Leopard
+ * // 2, Equus zebra, Zebra
+ * </code></div>
+ */
 p5.XML = function () {
   this.name = null; //done
   this.attributes = {}; //done
@@ -750,3 +791,4 @@ p5.XML.prototype._setAttributes = function(node) {
   this.attributes = att;
 };
 
+module.exports = p5.XML;