Not sending Content-Type on requests

[maxlinc]

You find interesting things while intercepting via proxies...

php-opencloud is sending Content-Type on authentication (see here), but not on other services.

I guess OpenRepose is being lenient and assuming JSON rather than XML. It is more correct (and less likely to cause problems with proxies or other middleware) if you send the Content-Type, though.

I don't think this PR covers all the necessary posts. Does each post need to be changed, or is it possible to change in the HTTP client?

[jamiehannaford]

@maxlinc The problem is with file uploads, i.e. Swift object transfers. Many people will not manually set a content-type - so the SDK will have to guess. We've done this before and the majority of times it got the file MIME type wrong. If you leave it blank, the API will do the content guessing for you - and do a much better job. What I can look at doing, however, is setting the Content-Type header for all other requests that contain a JSON body.

[jamiehannaford]

This is hopefully fixed now. I'll reference this issue in a commit.