Allowing more options to style pretix shops (#1585)

* Fix caching issues in SASS compilation

* Allow to set a custom page background color

* Allow to disable round corners

* Support larger header pictures

* Allow to show title despite header

* Move language picker

* FIx widget styles

src/pretix/base/settings.py

@@ -1298,6 +1298,14 @@ Your {event} team"""))
         'default': '#D36060',
         'type': str
     },
+    'theme_color_background': {
+        'default': '#FFFFFF',
+        'type': str
+    },
+    'theme_round_borders': {
+        'default': 'True',
+        'type': bool
+    },
     'primary_font': {
         'default': 'Open Sans',
         'type': str
@@ -1322,6 +1330,22 @@ Your {event} team"""))
         'default': None,
         'type': File
     },
+    'logo_image_large': {
+        'default': 'False',
+        'type': bool
+    },
+    'logo_show_title': {
+        'default': 'True',
+        'type': bool
+    },
+    'organizer_logo_image': {
+        'default': None,
+        'type': File
+    },
+    'organizer_logo_image_large': {
+        'default': 'False',
+        'type': bool
+    },
     'og_image': {
         'default': None,
         'type': File