Apply gofmt

This includes all of the methods mentioned in this blog post:
https://developer.github.com/changes/2014-03-18-paginating-method-changes/
as well as a handful of others I found.  Sadly, this is a breaking
change for many of these methods because it changes the method
signature, but with yesterday's API change these methods are now broken
anyway. :(

it's not the cleanest, but it works.

instead of inspecting the JSON tags on the struct fields directly,
actually run it through JSON marshalling and unmarshalling, then compare
those results.

graceful.Server was made private in 05c2ca7e, but I think the increased
flexibility you get with being able to provide your own TLS options
(etc.) outweighs the API complexity of an additional type.

This bugfix brought to you by `go vet`

I'm not particularly satisfied with the solution here. Maybe the answer
is "more middleware," but I'm not sure.

This fixes up the last few compilation errors caused by the UrlParams =>
URLParams rename.

- ListCodeFrequency
- ListPunchCard

- use Timestamp for Week fields instead of int
- rename WeekHash to WeekStats

So it appears GitHub already supports multiple types of subscriptions:
repositories and threads.  I'm leaving the data type simply as
'Subscription', but am updating the method names to avoid confusion,
since they're both part of the ActivitiesService.

mark RateLimit method as deprecated in favor of RateLimits which returns
both the core and search limits. (see deprecation notice in API docs:
https://developer.github.com/v3/rate_limit/#deprecation-notice)

depending on who people are using rate.Reset this may or may not be a
breaking change, since Timestamp supports all of the exported methods
from time.Time.

this is a breaking change, but this was only recently added so I'm not
too worried.  This also seems the best way to handle sub-namespaces on
this method.

Includes basic CRUD methods on repositories as well as listing branches
and tags.

- Repositories.Delete
- Repositories.ListTeams
- Repositories.ListTags
- Repositories.GetBranch

I changed my mind.  This really is terribly verbose, and looking at the
design of the API, it seems unlikely GitHub would change the
subscriptions endpoint to include anything other that repositories.  And
if they do...  well, we'll deal with it.

this is a breaking change, but there's no way around that, since the opt
param was left off initially.

(I kinda hate how long some of these names are... I'd much rather just
call them "subscriptions", but the API docs is pretty consistent about
calling them "repository subscriptions", so that's what we go with.
Maybe the intend to later add other kinds of subscriptions?)

add tests for User.Edit and User.GetKey