Created new metadata app and move all code relating metadata to it

apps/metadata/admin.py

@@ -0,0 +1,30 @@
+from django.contrib import admin
+
+from metadata.models import MetadataType, MetadataSet, MetadataSetItem, \
+    DocumentMetadata
+
+
+class MetadataTypeAdmin(admin.ModelAdmin):
+    list_display = ('name', 'title', 'default', 'lookup')
+
+
+class MetadataSetItemInline(admin.StackedInline):
+    model = MetadataSetItem
+    extra = 1
+    classes = ('collapse-open',)
+    allow_add = True
+
+
+class DocumentMetadataInline(admin.StackedInline):
+    model = DocumentMetadata
+    extra = 0
+    classes = ('collapse-open',)
+    allow_add = False
+
+
+class MetadataSetAdmin(admin.ModelAdmin):
+    inlines = [MetadataSetItemInline]
+
+
+admin.site.register(MetadataType, MetadataTypeAdmin)
+admin.site.register(MetadataSet, MetadataSetAdmin)