Add docs for org status api
Add heading for response formats for pull requests
Explain and deprecate the merge_commit_sha

The merge_commit_sha is often misunderstood. It is internal GitHub
plumbing that just happens to be part of the public API. Explain it
(to reduce the confusion for the current version of the API), and
announce plans to remove it from the next version of the API.
Link merge_commit_sha explanation to deprecation
Improve "mergability" docs

Thanks to @gjtorikian for the suggestion.
start file crud docs with creation

This needs updating once we make a decision on how passing
author/committer will work, and probably something better for the
response.
add update-file docs
add delete-file docs

This obviously needs a better response example, if only because the
commit message is about *adding* the readme.
Merge remote-tracking branch 'github/master'
Merge github/master from upstream
Revert "Add docs for org status api"

This reverts commit f18879112096c122b962c3d0e110311785caf695, which was
accidentally added to master. That commit belongs on a branch until it
becomes public in the upstream repo (github/developer.github.com).
Get some starting words for the Guide
Add file manipulation guide
Address review
Improve samples
Update file-manipulation.md
It's the original SHA, man.
Clarify supported media types for Contents API
Merge pull request #244 from github/clarify-supported-media-types-for-repo-contents-api

Clarify supported media types for Repository Contents API
Fix URLs in symlink example response