Moved classes to core and made minimal edits.

* views/js/main.js : added "|" to bob{} regex andn edited some comments.
Quick fix on calling loadPage().
* index.php : Moved add/removeCartProduct() and isInCart from class User
to Products. Seems to better fit.
* views/view.base.php : edited some comments.
* core/* : Moved and splitted _database.php, _templating.php and
_typo3_db.php to core/ and made the needed edits in _init.php.
* views/view.details.php : Adapted to Class edits.
* views/view.products.php : Comment edit.

Notes:
I've added __db.sql in core/ to allow testing the repo. It contains all
tables required to run the "CMS".