Allow undeprecation of an image.
Allow undeprecation of an image.

Closes #851

t-tran/libcloud,erjohnso/libcloud,andrewsomething/libcloud,NexusIS/libcloud,mistio/libcloud,SecurityCompass/libcloud,iPlantCollaborativeOpenSource/libcloud,SecurityCompass/libcloud,vongazman/libcloud,NexusIS/libcloud,watermelo/libcloud,Scalr/libcloud,illfelder/libcloud,iPlantCollaborativeOpenSource/libcloud,samuelchong/libcloud,StackPointCloud/libcloud,andrewsomething/libcloud,samuelchong/libcloud,mistio/libcloud,samuelchong/libcloud,SecurityCompass/libcloud,vongazman/libcloud,ByteInternet/libcloud,watermelo/libcloud,techhat/libcloud,StackPointCloud/libcloud,apache/libcloud,pquentin/libcloud,Scalr/libcloud,andrewsomething/libcloud,ByteInternet/libcloud,mgogoulos/libcloud,mgogoulos/libcloud,illfelder/libcloud,Kami/libcloud,erjohnso/libcloud,pquentin/libcloud,ByteInternet/libcloud,iPlantCollaborativeOpenSource/libcloud,illfelder/libcloud,Scalr/libcloud,techhat/libcloud,watermelo/libcloud,pquentin/libcloud,t-tran/libcloud,NexusIS/libcloud,ZuluPro/libcloud,ZuluPro/libcloud,Kami/libcloud,mistio/libcloud,apache/libcloud,StackPointCloud/libcloud,vongazman/libcloud,erjohnso/libcloud,mgogoulos/libcloud,apache/libcloud,techhat/libcloud,ZuluPro/libcloud,t-tran/libcloud,Kami/libcloud