PSR-4 autoloading

This moves us to PSR-4 autoloading without changing the directory structure.
minor #670 PSR-4 Autoloading (GrahamCampbell)

This PR was merged into the 1.0.x-dev branch.

Discussion
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PSR-4 Autoloading

This moves us to PSR-4 autoloading without changing the directory structure.

Commits
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c963669 PSR-4 autoloading