Hello,
there is critical bug in file lib/Microsoft/WindowsAzure/Storage/Blob.php, at line 1864.
 
When include paths are not set as expected, require_once() fails.
 
Solution: Let autoloader do its job. Use this code instead:
 
class_exists('Microsoft_WindowsAzure_Storage_Blob_Stream');
 
PHP will look for specified class and it kicks autoloader...