Made batch creation and execution threads aware of sys.excepthook.

Updated both instances to use `rattail.threads.Thread` instead of
`threading.Thread`.  This way if an exception occurs within the
thread, the registered handler will be invoked.

rattail/pyramid/views/batches/core.py

@@ -26,8 +26,6 @@
 ``rattail.pyramid.views.batches.core`` -- Core Batch Views
 """
 
-import threading
-
 from pyramid.httpexceptions import HTTPFound
 from pyramid.renderers import render_to_response
 
@@ -42,6 +40,7 @@ from edbob.pyramid.views import SearchableAlchemyGridView, CrudView, View
 
 import rattail
 from rattail import batches
+from rattail.threads import Thread
 
 
 class BatchesGrid(SearchableAlchemyGridView):
@@ -165,7 +164,7 @@ class ExecuteBatch(View):
             return HTTPFound(location=self.request.route_url('batches'))
 
         progress = SessionProgress(self.request.session, 'batch.execute')
-        thread = threading.Thread(target=self.execute_batch, args=(batch, progress))
+        thread = Thread(target=self.execute_batch, args=(batch, progress))
         thread.start()
         kwargs = {
             'key': 'batch.execute',

rattail/pyramid/views/products.py

@@ -26,8 +26,6 @@
 ``rattail.pyramid.views.products`` -- Product Views
 """
 
-import threading
-
 from sqlalchemy import and_
 from sqlalchemy.orm import joinedload
 
@@ -45,6 +43,7 @@ import rattail
 import rattail.labels
 from rattail import sil
 from rattail import batches
+from rattail.threads import Thread
 from rattail.exceptions import LabelPrintingError
 from rattail.pyramid.forms import GPCFieldRenderer, PriceFieldRenderer
 
@@ -292,7 +291,7 @@ class CreateProductsBatch(ProductsGrid):
                             return HTTPFound(location=url)
                     
                     progress = SessionProgress(self.request.session, 'products.batch')
-                    thread = threading.Thread(target=self.make_batch, args=(provider, progress))
+                    thread = Thread(target=self.make_batch, args=(provider, progress))
                     thread.start()
                     kwargs = {
                         'key': 'products.batch',