Fix autoload bug. Fixes #373.
bug #374 Fix autoload bug. Fixes #373. (mdavis1982)

This PR was submitted for the develop branch but it was merged into the 2.1.x-dev branch instead (closes #374).

Discussion
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Fix autoload bug. Fixes #373.

Related to issue #373, This fixes the problem whereby locating the `autoload.php` in a non-standard composer install (using the `vendor-dir`option) fails.

Commits
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8c27c39 Fix autoload bug. Fixes #373.