Return not_implemented for options that have not been implemented that can't blindly be ignored.

[JustinKyleJames]

There are many options for the supported API's that we don't currently support. Depending on the context, some can be ignored while others should not be blindly ignored.

For the latter, we should return the not_implemented HTTP response.

An example of the former could be versionId on DeleteObject. Since we don't support versions, it might make sense to just continue with the deletion.

An example of the latter might be If-Modified-Since on GetObject.

These are judgement calls. In this issue we will go through each option and decide which of the two fit and implement them. This will not be in 0.2.0.

[alanking]

This will not be in 0.2.0.

Should we make a new milestone so that this does have a home?

[trel]

sure - 0.3.0 here we come.

[alanking]

We did it. Feel free to... undo that. :)