PagSeguro : Compatibility with PrestaShop 1.4, 1.5 and 1.6

Compatibility with prestashop 1.4, 1.5 and 1.6.

Added some new features:

- Conciliate transactions
- Recovery abandoned transactions
Done @ https://github.com/cegoncalves/PrestaShop-modules/commit/f1435142118ccee89fa8cf3bdbd51229aeeb1a34