Configurable rate rounding (#5734)

* added invoice hydration of the issuer object
* added "rate calculator" mode
* new config to select rounding mode
* replace static calls with dependency injection

tests/Invoice/Renderer/DebugRendererTest.php

@@ -109,6 +109,29 @@ class DebugRendererTest extends TestCase
             'invoice.subtotal',
             'invoice.subtotal_nc',
             'invoice.subtotal_plain',
+            'issuer.address',
+            'issuer.address_line1',
+            'issuer.address_line2',
+            'issuer.address_line3',
+            'issuer.buyer_reference',
+            'issuer.city',
+            'issuer.comment',
+            'issuer.company',
+            'issuer.contact',
+            'issuer.country',
+            'issuer.country_name',
+            'issuer.email',
+            'issuer.fax',
+            'issuer.homepage',
+            'issuer.id',
+            'issuer.invoice_text',
+            'issuer.meta.foo-customer',
+            'issuer.mobile',
+            'issuer.name',
+            'issuer.number',
+            'issuer.phone',
+            'issuer.postcode',
+            'issuer.vat_id',
             'template.name',
             'template.company',
             'template.country',