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

tests/PayPal/Test/Core/PPLoggingManagerTest.php

@@ -0,0 +1,64 @@
+<?php
+use PayPal\Core\PPLoggingManager;
+/**
+ * Test class for PPLoggingManager.
+ *
+ */
+class PPLoggingManagerTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var PPLoggingManager
+     */
+    protected $object;
+
+    /**
+     * Sets up the fixture, for example, opens a network connection.
+     * This method is called before a test is executed.
+     */
+    protected function setUp()
+    {
+        $this->object = new PPLoggingManager('InvoiceTest');
+    }
+
+    /**
+     * Tears down the fixture, for example, closes a network connection.
+     * This method is called after a test is executed.
+     */
+    protected function tearDown()
+    {
+    }
+
+    /**
+     * @test
+     */
+    public function testError()
+    {
+    	 $this->object->error('Test Error Message');
+
+    }
+
+    /**
+     * @test
+     */
+    public function testWarning()
+    {
+         $this->object->warning('Test Warning Message');
+    }
+
+    /**
+     * @test
+     */
+    public function testInfo()
+    {
+        $this->object->info('Test info Message');
+    }
+
+    /**
+     * @test
+     */
+    public function testFine()
+    {
+       $this->object->fine('Test fine Message');
+    }
+}
+?>