Rename instantiate! to build, no more raising in build, no saving in build, no seeding of aspects in build.

This reverts commit 1481056a.

This reverts commit fb70dc8c, reversing
changes made to 53fef63a.

Conflicts:

	pkg/fedora/diaspora-setup
	pkg/ubuntu/diaspora-setup
	public/stylesheets/sass/application.sass
	spec/models/user/attack_vectors_spec.rb

Remove downcasing of diaspora_handle, verify that diaspora_handle querying and validation is case insensitive.

username can be any case, but diaspora handle should always, always, ALWAYS be lowercase, for webfinger reasons

RegistrationsController#create deals with validation errors. Username, email, password now required on sign-up.

Add spec for validation hook

RS, IZ; Pod url moved to app_config.yml, app_config.yml refactored, diaspora_handle now set based on APP_CONFIG