Revert "fix generated_image_url when generated_images_dir is set"

This reverts commit 5ed70d60254645a46ddf8ed1cf78a57adc917815.

Conflicts:
	lib/compass-rails/patches/3_1.rb
Merge pull request #122 from Compass/1-1-stable

Revert "fix generated_image_url when generated_images_dir is set"