Add #version_exists?
Refactor active_versions
Only return version url if version exists
Merge pull request #1092 from tmaier/master

Add method #version_exists?
Don't enforce the move_to_cache config option on versions, closes #1088
fix busted tests on ruby 1.8.7 (1.9.3 also re-checked)
Merge pull request #1109 from woodwardjd/maintain_file_conversion_across_processing

fix busted tests on ruby 1.8.7 (1.9.3 also re-checked)
Update URLs to carrierwaveuploader/carrierwave
Merge branch 'master' into cache_id
Fix recently added move_to_cache specs that were using the old cache ID format