Refactor error messages to be shared

This will be used by other views to display their error messages, so
make it general enough to accomplish the task.
Make Service nested inside Church.

We make routes and forms to include Service as part of a Church
typically.

Conflicts:
	app/controllers/churches_controller.rb
	app/models/church.rb
	app/models/service.rb
	config/routes.rb
Fix tests that broke with previous two commits

The previous two commits broke:

    1.  the routes for services because we changed them from
	"normal" to nested shallowly in church, and
    2.  the refactored shared error messages weren't propagated to the
	edit action for the user.

This fixes those problems so they work again.

Conflicts:
	app/views/users/edit.html.erb
Place more requirements on Church & Service

This makes sure that more attributes for the two models are required
so that we can't create values that are useless.
Test creation of Church with nested Service

These tests check that we can create a church with one nested service
as part of the form.
Require new church to have proper manager

This test makes sure that when a church is created that it is assigned
a manager by using the currently logged in user as that manager.
Merge branch 'master' of http://github.com/geisler/worship_together

Conflicts:
	app/controllers/churches_controller.rb
	app/models/church.rb
	app/models/service.rb
	app/views/users/_errors.html.erb
	app/views/users/edit.html.erb
	config/routes.rb
finished tests 11/23/14