install: multibyte string php-extension check added
Merge branch '1.1.3' of github.com:abantecart/abantecart-src into 1.1.3
Core: extension manager now contain few validation method from core/engine/extensions.php.
Table extension_dependencies added into db.
Control Panel: order totals extensions page changed. Children extensions check added for disabling extension.
total-extensions edit-page bugfixes.

Storefront: APromotion hooks appliings inside total-calculation loop removed.
Merge remote-tracking branch 'origin/1.1.3' into 1.1.3

Conflicts:
	public_html/core/lib/cart.php