Support for PHP<5.3 by not using __DIR__

git-svn-id: https://plugins.svn.wordpress.org/instamojo/trunk@887417 b8457f37-d9ea-0310-8a92-e5e31aec5664
Better messages and exception catching

git-svn-id: https://plugins.svn.wordpress.org/instamojo/trunk@887419 b8457f37-d9ea-0310-8a92-e5e31aec5664