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Added alias_method solution
I thought I'd add a small example of what could be done in case another gem included in your project uses CanCan as well.
Revert 80f847874b47b5e8ff6ad4d26ec89e49c177d516^ ... 80f847874b47b5e8ff6ad4d26ec89e49c177d516
Destroyed Changing Defaults (markdown)
switching to markdown
Updated Changing Defaults (textile => markdown)