state:resolved]

The test case now mimicks the template environment more closely, so it's
possible to use render, load helper dependencies.

This also fixes assert_select, and similar assertions. Because view tests
and helpers generally don't render full templates assert_select looks
first in rendered and then in output_buffer to find the rendered output.

Additional `master'-only changes: Made the Action Pack Rakefile run the
ActionView::TestCase tests, and made ActionView::Rendering#_render_text
always return a string.
Signed-off-by: NJoshua Peek <josh@joshpeek.com>