Removing Dependency from SDK Core Project

- Copied files required for Rest API SDK
- Removed PPApiContext and directly connected APIContext with PPConfigManager
- Removed duplicate data storage of configuration and credentials.
- Code Style Fixes
- Remove build.xml file as it is not required anymore
- Updated the samples
- Updated the documentations

lib/PayPal/Api/ItemList.php

@@ -17,14 +17,16 @@ class ItemList extends PPModel
     /**
      * Construct an empty list.
      */
-    function __construct() {
+    function __construct()
+    {
         $this->items = array();
     }
 
-    /** 
+    /**
      * Is this list empty?
      */
-    public function isEmpty() {
+    public function isEmpty()
+    {
         return empty($this->items);
     }
 
@@ -67,26 +69,30 @@ class ItemList extends PPModel
         return $this;
     }
 
-	/**
-	 * Append an item to the list.
-	 * @return PayPal\Api\Item
-	 */
-	public function addItem($item) {
-		return $this->setItems(
-			array_merge($this->items, array($item))
-		);
-	}
+    /**
+     * Append an item to the list.
+     *
+     * @return PayPal\Api\Item
+     */
+    public function addItem($item)
+    {
+        return $this->setItems(
+            array_merge($this->items, array($item))
+        );
+    }
 
-	/**
-	 * Remove an item from the list.
-	 * Items are compared using === comparision (PHP.net)
-	 * @return PayPal\Api\Item
-	 */
-	public function removeItem($item) {
-		return $this->setItems(
-			array_diff($this->items, array($item))
-		);
-	}
+    /**
+     * Remove an item from the list.
+     * Items are compared using === comparision (PHP.net)
+     *
+     * @return PayPal\Api\Item
+     */
+    public function removeItem($item)
+    {
+        return $this->setItems(
+            array_diff($this->items, array($item))
+        );
+    }
 
     /**
      * Get Shipping Address