new_options should be optional in asset_update_operation

[vikramrajkumar]

From @theoreticalbts on February 15, 2016 15:28

new_options should be optional allowing asset_update_operation with semantics of "don't change the options" (but maybe change the issuer).

It's going to be hard to implement this change without breaking protocol compatibility.

Copied from original issue: cryptonomex/graphene#580

Update: bitshares/bsips#159 will cover this.

[vikramrajkumar]

From @abitmore on February 16, 2016 5:34

I've done something related. CER could be optional in this commit. Need a pull request?

In regards to other options, I think maybe only blacklists and whitelists will matter since they may be large arrays. And maybe asset_description.

Here is a serious (GUI) bug report related, don't know whether it's fixed so I just submitted an issue to graphene_ui repo.