Remove more unused backwards compatibility code

Since pytest.urls() now raises an exception this code path will
never be taken anymore.
Add djangodb funcarg

This has the same effect of marking the function with
@pytest.mark.djangodb but allows a funcarg to request the database
which is cleaner then having to know a particular funcarg needs the
mark.  It is actually required since the mark will only enable the
database *after* the funcargs have done their setup.
Document the djangodb funcarg
Small cleanup of code for removed functionality

Since the backwards compatible code is gone we can do this in it's
logical space rather then needing to do this upfront.
Merge pelme's changes into lazy_django

Conflicts:
	pytest_django/funcargs.py
	pytest_django/plugin.py
Initial port to pytest 2.3 API

This uses the new fixtures API which solves a number of issues
pytest-django has.  It involves fairly large refactoring.  So
far this isn't complete yet and could use more tests.
Cleanup tests

Remove unused code and make use of some more testdir features.  Also
make the intend a bit clearer by relying on less constants and
substitutions.  This makes for a little more typing but is still
succinct and makes things readable by all information being together.
Use a new version number
Move conftest.py to tests directory

The only useful thing in there was only enabling the pytester plugin
since the sys.path hack is just to crude.  The tests need to be run
in "setup.py develop" mode anyway because of the silly environment.
Extend fixtures tests

This renames the funcarg tests to fixtures tests and extends them
as well.  Notably it adds tests for the database fixtures and
extends the tests for the settings fixture.  The latter showing
that the current implementation is not good enough.
Remove redundant import

This should have made it into the last commit but git clearly
disagreed with me over that.  Oh well.
Properly copy and restore the settings
Consolidate the database tests

Move the database tests from test_fixtures and test_transactions
into one test module.  This now tests the databases access via
fixtures and using the django_db marker.
Add test for blocking db access in fixtures
Cleanup live_server tests

This expands on the tests for the live_server fixture and moves them
together with the tests for the other fixtures.  It also fixes a bug
when the db fixture was combined with live_server.
Ignore emacs backup files
Small cleanup on for the pytest.mark.url tests
Depend on newer py.test for better finalizer ordering

The finalizer ordering has been made more relyable in pytest 2.3.4.
Fixup of db reuse tests
Merge branch 'pytest23' into lazy_django

Conflicts:
	tests/test_db_setup.py