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/Currency.php

@@ -4,45 +4,50 @@ namespace PayPal\Api;
 use PayPal\Common\PPModel;
 use PayPal\Rest\ApiContext;
 
-class Currency extends PPModel {
-	/**
-	 * 3 letter currency code
-	 *
-	 * @param string $currency
-	 */
-	public function setCurrency($currency) {
-		$this->currency = $currency;
-		return $this;
-	}
+class Currency extends PPModel
+{
+    /**
+     * 3 letter currency code
+     *
+     * @param string $currency
+     */
+    public function setCurrency($currency)
+    {
+        $this->currency = $currency;
+        return $this;
+    }
 
-	/**
-	 * 3 letter currency code
-	 *
-	 * @return string
-	 */
-	public function getCurrency() {
-		return $this->currency;
-	}
+    /**
+     * 3 letter currency code
+     *
+     * @return string
+     */
+    public function getCurrency()
+    {
+        return $this->currency;
+    }
 
 
-	/**
-	 * amount upto 2 decimals represented as string
-	 *
-	 * @param string $value
-	 */
-	public function setValue($value) {
-		$this->value = $value;
-		return $this;
-	}
+    /**
+     * amount upto 2 decimals represented as string
+     *
+     * @param string $value
+     */
+    public function setValue($value)
+    {
+        $this->value = $value;
+        return $this;
+    }
 
-	/**
-	 * amount upto 2 decimals represented as string
-	 *
-	 * @return string
-	 */
-	public function getValue() {
-		return $this->value;
-	}
+    /**
+     * amount upto 2 decimals represented as string
+     *
+     * @return string
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
 
 
 }