Switch to full app paths

Instead of inserting the path of the apps into the Python app,
the apps are now referenced by their full import path.

This solves name clashes with external or native Python libraries.
Example: Mayan statistics app vs. Python new statistics library.

Every app reference is now prepended with 'mayan.apps'.

Existing config.yml files need to be updated manually.

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

mayan/apps/document_states/forms.py

@@ -9,7 +9,7 @@ from django.forms.formsets import formset_factory
 from django.utils.module_loading import import_string
 from django.utils.translation import ugettext_lazy as _
 
-from common.forms import DynamicModelForm
+from mayan.apps.common.forms import DynamicModelForm
 
 from .classes import WorkflowAction
 from .models import (