Cleanups in the order checkout process

[Jacopo Cappellato]

Hi,

with rev. 434334 I've split up the 
CheckOutEvents.finalizeOrderEntry(...) method into two ones:

1) CheckOutEvents.finalizeOrderEntry(...) where all the actions are taken
2) (new) CheckOutEvents.determineNextFinalizeStep(...) where the next 
step is determined: I've simply moved the logic at the end of the 
original finalizeOrderEntry method into this new one to make things a 
bit more clear (hopefully)

The next step should be that using these new methods every time we need 
to perform an order checkout (both in order manager and ecommerce); 
right now it seems to me that we have a lot of duplicated methods that 
performs similar tasks in slightly different ways... and this is a bit 
scaring.

For example: CheckOutEvents.setCheckOutPages(...) (and related methods) 
are very similar to the CheckOutEvents.finalizeOrderEntry(...)

I'd like to get your feedback about this.

Thanks,

Jacopo