Merge pull request #56 from jeichorn/master

Improve error message of InjectionException with an invalid parameter
Fix readme example code errors
Php 5.4 array notation to ease reading
Fixed typo in readme
Merge pull request #57 from staabm/patch-1

Php 5.4 array notation to ease reading
Merge pull request #58 from staabm/patch-2

Fixed typo in readme
Use PSR-4 autoloading
Merge pull request #59 from gigablah/psr4

Use PSR-4 autoloading for Composer