#863: clearBlobPages 'text' parameter is unused.
#874: BlobService.copyBlob doc comments are wrong
#861: acquireLease has two parameters for specifying LeaseDuration: leaseDuration and optionsOrCallback.leaseDuration. Only optionsOrCallback.leaseDuration is actually used.
Add parameter validation to give appropriate named errors
Merge pull request #87 from andrerod/storage_fixes

Storage fixes