documentation mislead on using post_options

[Jerome Raezweb]

Hi,

 after tried to implement a simple post, I found some misleading examples in the documentation here:
 http://docs.openstack.org/developer/python-swiftclient/service-api.html#post

 you have "post_options = {"header": "X-Delete-After:86400"}"

 but if you look at the code here:
 https://github.com/openstack/python-swiftclient/blob/master/swiftclient/utils.py#L151

 you'll see that split_request_headers expect options to be a list.
 so, if you apply the example, the code will try to find a ":" in "X" and fail.

 the correct example should be "post_options = {"header": ["X-Delete-After:86400"]}"

Thanks