Move add_to_class functions to their own module

* The new module is called methods.py and found on each app.
* Add keyword arguments to add_to_class instances.
* Remove catch all exception handling for the check in and
  check out views.
* Improve checkouts tests code reducing redundant code.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/document_parsing/methods.py

@@ -0,0 +1,28 @@
+from __future__ import unicode_literals
+
+from datetime import timedelta
+
+from django.utils.timezone import now
+
+from mayan.apps.common.settings import settings_db_sync_task_delay
+
+from .events import event_parsing_document_version_submit
+from .tasks import task_parse_document_version
+
+
+def method_document_parsing_submit(self):
+    latest_version = self.latest_version
+    # Don't error out if document has no version
+    if latest_version:
+        latest_version.submit_for_parsing()
+
+
+def method_document_version_parsing_submit(self):
+    event_parsing_document_version_submit.commit(
+        action_object=self.document, target=self
+    )
+
+    task_parse_document_version.apply_async(
+        eta=now() + timedelta(seconds=settings_db_sync_task_delay.value),
+        kwargs={'document_version_pk': self.pk},
+    )