Remove CORE-POS web views logic

all the views are still visible in our app, but the view logic belongs in
tailbone-corepos now

rattail_demo/web/views/__init__.py

@@ -37,7 +37,7 @@ def includeme(config):
     config.include('tailbone.views.vendors')
 
     # core-pos views
-    config.include('rattail_demo.web.views.corepos')
+    config.include('tailbone_corepos.views.corepos')
 
     # batch views
     config.include('tailbone.views.handheld')