Remove PHP 5.3 support.

5.3 is now [EOL] and there is no reason for us to continue to support
this version from this moment on. Users needing PHP 5.3 support can use
the previous version.

[EOL]: http://php.net/archive/2014.php#id2014-08-14-1
Use php 5.4 array syntax.
Update composer for phpunit 4.
Merge pull request #5 from gaillard/master

Remove php 5.3 support, use 5.4 array syntax and update to phpunit 4.
Use shields.io for the badge.
Add badges for packagist.
Specify the testsuite in the phpunit.xml.

This is done so that it doesn't have to be specified on the phpunit
command line.
Enable strict code coverage.
Remove --dev from composer install.

composer install installs dev dependencies by default.
Convert usage of phpunit to a library.

This interface is more programmatic and easier to handle code coverage
report for.
Convert usage of phpcs to a library.