Allow fully qualified or short references to be used to generate "reference" Uri

[astrohart]

Fixes #1933

30 Jan 2019 Updated the second overload of the ApiUrls.Reference to remove any occurrence of refs/ from the string passed in for its referenceName parameter, so a reference from a tag retrievd with the API can be used natively with other reference APIs, such as Delete Reference.

[ryangribble]

Any reason why you've removed the .dotsettings resharper settings file @astrohart ?

[ryangribble]

I'm ok with this change - I agree it is robust and handles both the "existing" behaviour where refs/ wasnt specified in the argument, plus works with "new" behaviour where you quite rightly point out, a ref received from another endpoint should be able to be passed straight into the delete method and work.

It actually stems from the GitHub Api documentation itself, where it indicates the URI for patch and delete calls is /repos/:owner/:repo/git/refs/:ref (ie :ref should not include prefix of refs/) yet on the create call requires the "fully qualified ref" to be specified:

ref | string | Required. The name of the fully qualified reference (ie: refs/heads/master). If it doesn't start with 'refs' and have at least two slashes, it will be rejected.

Nevertheless I think this change makes things less surprising and better for users so I'm cool with it...

I would ask 2 things though:

• if we no longer require the ref to be formatted in a particular way, could we remove that XmlComment in the code, that tells users not to pass in refs/ ?
• Since the Update (patch) endpoint has the same behaviour, can we ensure this is also updated/tested in octokit with similar changes? (i am on mobile so haven't checked if it uses the same ApiUrl overload and/or has the same comment guidance about not passing refs/ in)

[shiftkey]

I accidentally closed this out because I could rewrite the branch to update the history and drop the tooling commit. I've opened #2104 to restart the process and see if we can land the fix.