Merge pull request #84 from itnova/develop-2.1.1

Add adyen_event collection model
rename button id and title
extra check if values are available if not don't show the label
optimize code for calculation of additional data signature
Fixes #85 added configuration item for scanners that press a enter after the barcode is read. If this setting is enabled then the javascript that check if the reading is done can be disabled and the form automatically can be submitted by the enter keyboard stroke.
Fixes #86 fix that payment type in Payment Information block of the order is showing.
Fixes  #87 added button to pay with Cash. Fix for cash payments that psp reference number is saved on the magento side.
#77 implemented a setting that when billing and shipping addresses are different the payment method open invoice will not be shown.
Fixes #88 check if the values are zero if not only then show the total (this is visable on the order confirmation email)
#77 extra check if all the parameters are there before using it resolved conflicts if you add order in backend
#90 convert special characters to UTF-8
Revert "#90 convert special characters to UTF-8"

This reverts commit d6b867a68ae931ae9d5faaacec1e6f455d5a5c57.
Fixes #90 convert special characters to UTF-8
Fixes #92 add option for shopper to not save his creditcard for OneClick purposes
Fixes #70 enable installments in payment method OneClick, fixed Adyen Creditcard installments if CSE is enabled and removed some duplicate code
[BUGFIX] Fix incorrect rounding in invoice row
Merge pull request #93 from FrankStappers/develop-2.1.1

[BUGFIX] Fix incorrect rounding in invoice row
Fixes #94 fix vat rounding for openinvoice
Fixes #95 implement support for cash drawer
#96 log the CANCEL_OR_REFUND notification