Silence the version import error
Remove unused imports
Remove unused imports
Fix import flake errors
Get rid of mutable default arguments while I'm here.
Remove unused imports
Remove unused imports
Remove unused imports
Fix unused variable assignment
Fix unused variable assignment
Fix unused variable assignment
Silence unused import
Remove unused imports
Silence the import error
Remove unused import
Import from dataset and in init to get rid of Travis build error.
Explicitly import sqlalchemy functions and classes where needed

These have been removed from openspending/model/meta.py from which
they were magically imported. They should be explicitly imported
so maintainers will know from where these functions and classes
come instead of needing to chase them down.
Explicitly import sqlalchemy and openspending.model classes and functions

This gets celery up and running as it now imports explicitly from
the openspending.model modules (which in turn import explicitly
from sqlalchemy).

Explicit is better than implicit.
Explicit imports instead of indirect imports via other modules

Some external packages/modules (mostly SQLAlchemy but also a
url generator in the template helper module) is loaded by some
modules and then elsewhere these external packages/modules are
imported through those openspending modules. This makes it
harder to read the codebase and causes unused imports since the
external modules aren't used by the intermediate module.

This commit also removes the dataset_country module from
openspending.model since that is not used (so we did not need
to import it for SQLAlchemy (it wasn't imported before) and
therefore could be removed.

This gets tests working and passing again.
Move DatasetTerritory and DatasetLanguage into dataset module

DatasetTerritory and DatasetLanguage were both in their own modules
which they didn't need to be and one would expect all database
related classes to be in the database module instead of a module
called database_territory or database_language (if one sees the
database module first).