Man pages should be the canonical source of hub documentation. People
should use `man help hub` instead of viewing the README, which might not
even correspond to the version they have installed.

This ends the confusing man page build system in which parts of the
README are injected into `hub.1.ronn` source file, deletes the Rakefile
and removes rake from gem bundle.

The examples are deleted because they are now inlined with individual
command documentation. So did the documentation for all hub commands get
deleted from main man page in favor of individual man pages.

However, this makes main man page have absolutely no listing of which
commands are available. This will get addressed as we go forward.

Fixes #463 and #948

This is so the tags from the automatically-added remote (typically
someone's fork) don't spill in and mix with the current tags.

Due to some breaking changes in Go's standard library which we need,
e.g., https://code.google.com/p/go/source/diff?spec=svn733fefb1deae5490f2d6fcf498667a9077f92a42&r=733fefb1deae5490f2d6fcf498667a9077f92a42&format=side&path=/src/pkg/net/http/transport.go

Technically, anything in the third argument is passes as a string, so you can look at any file if you know the hash (for instance, `blob/HASH/app/index.js`. However, having the issue number passed seems to me to be something really useful to my workflow, so I was hoping to find something in the documentation about it. 

Another possibility would be to enable a fourth argument for issue number. I'm happy to do a PR for this if something things it might be of more worth than just this edit.

- "git protocol for read and ssh for write" had introduced
  additional expectations of behavior.

Updated Homebrew recipe has been merged:
https://github.com/Homebrew/homebrew/commit/a746c26f8a7a6dd64850ba2cb9e76363bfca41e0

- Ruby is not required at runtime anymore
- Most installation instructions are now obsolete. Will need to write
  new instructions when we distribute precompiled binaries.
- Remove tedious parts about slowness. It's not slow anymore!

Closes #517 [ci skip]

[ci skip]

Fixes #421

This feature is likely to get dropped from GitHub API in the near
future. The alternative is to simply create a new pull-request and
reference the original issue in the description.

[ci skip]

Signed-off-by: NTimothy Gu <timothygu99@gmail.com>

Don't suggest standalone install via curl anymore because:

- hub may not be a single script in the near future
- `rake install` handles the Windows executable as well

Emulates the interface of `git commit`:

  $ hub pull-request -m "This is my title"
  $ hub pull-request -F /path/to/message.txt
  $ hub pull-request -F -

The old way of passing in just title is deprecated

  $ hub pull-request "Deprecated title"

Fixes #183

Fixes #232, references #270

Fixes #254

It doesn't add a remote anymore, as it isn't needed.