Updated composer config.

CakePHP 2.x releases are now available on packagist.
Revert "Merge pull request #31 from ADmad/master"

Reverting back to using the pear package for CakePHP as using packagist
included tests in core which causes problems with autoloading.

This change was broken anyway since updating the core path in index.php
was missed.

This reverts commit 425158d47b3c95a297fd5ae6a60b8b099b285c9c, reversing
changes made to b9dcfbf317a700a7478a38362df2fe2723057f04.
Better environment management

Use an external package for dsn parsing, and minimize the
logic required in the app template
lock dsn parsing to specific version
Ensure database connection is utf8 by default
Remove reference to a file that no-longer exists