Fixed conflict with export div and scrollY

* The ExportManager now checks if the scrollY is configured in the
TableConfiguration to append the new div in relation to the DataTables
scroll div
* The footer row is now included only if the table contains a filterable
column
* Added a new IT
* Closes dandelion/issues#133
Added new IT for i18n

Linked with dandelion/issues#4
* Removed dead code
* Added doc for confGroup in TLDs
* New IT for the configuration loading
* New Thymeleaf processor allowing to enable a configuration group
* Cleaned code
* Removed the ConfigurationStoreTest because it really suck
* Linked with dandelion/issues#113