Many bugs and features

* Fixed filtration bug
* Fixed customer address being trimmed bug
* Reworked payments.ini saving
* Added events log (run with -log arg to see it)
* Added summary of accepted payments (menu->shop->accepted payments)
* Now you pay to provider for all parts in order, not for each
separately
* Now you can select date when you add payment for provider
* Changed "Total order price" text field for "Customer debt" text field
in frmAddCash
* Added margin auto-calculate functionality to frmNewPart