Integrated vfsStream better and made paths constants VFS-based

Signed-off-by: dchill42 <dchill42@gmail.com>
diff --git a/tests/mocks/autoloader.php b/tests/mocks/autoloader.php
index 88d016b..431c310 100644
--- a/tests/mocks/autoloader.php
+++ b/tests/mocks/autoloader.php
@@ -48,32 +48,32 @@
 
 		if (in_array($subclass, $ci_core))
 		{
-			$dir = BASEPATH.'core'.DIRECTORY_SEPARATOR;
+			$dir = SYSTEM_PATH.'core'.DIRECTORY_SEPARATOR;
 			$class = $subclass;
 		}
 		elseif (in_array($subclass, $ci_libraries))
 		{
-			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR;
+			$dir = SYSTEM_PATH.'libraries'.DIRECTORY_SEPARATOR;
 			$class = ($subclass === 'Driver_Library') ? 'Driver' : $subclass;
 		}
 		elseif (in_array($subclass, $ci_drivers))
 		{
-			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR.$subclass.DIRECTORY_SEPARATOR;
+			$dir = SYSTEM_PATH.'libraries'.DIRECTORY_SEPARATOR.$subclass.DIRECTORY_SEPARATOR;
 			$class = $subclass;
 		}
 		elseif (in_array(($parent = strtok($subclass, '_')), $ci_drivers)) {
-			$dir = BASEPATH.'libraries'.DIRECTORY_SEPARATOR.$parent.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
+			$dir = SYSTEM_PATH.'libraries'.DIRECTORY_SEPARATOR.$parent.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
 			$class = $subclass;
 		}
 		elseif (preg_match('/^CI_DB_(.+)_(driver|forge|result|utility)$/', $class, $m) && count($m) === 3)
 		{
-			$driver_path = BASEPATH.'database'.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
+			$driver_path = SYSTEM_PATH.'database'.DIRECTORY_SEPARATOR.'drivers'.DIRECTORY_SEPARATOR;
 			$dir = $driver_path.$m[1].DIRECTORY_SEPARATOR;
 			$file = $dir.$m[1].'_'.$m[2].'.php';
 		}
 		elseif (strpos($class, 'CI_DB') === 0)
 		{
-			$dir = BASEPATH.'database'.DIRECTORY_SEPARATOR;
+			$dir = SYSTEM_PATH.'database'.DIRECTORY_SEPARATOR;
 			$file = $dir.str_replace(array('CI_DB','active_record'), array('DB', 'active_rec'), $subclass).'.php';
 		}
 		else