Merge upstream typings.

[jtbaker]

Please fill in this template.

• Use a meaningful title for the pull request. Include the name of the package modified.
• Test the change in your own code. (Compile and run.)
• Add or edit tests to reflect the change. (Run with npm test.)
• Follow the advice from the readme.
• Avoid common mistakes.
• Run npm run lint package-name (or tsc if no tslint.json is present).

Select one of these and delete the others:

If adding a new definition:

• The package does not already provide its own types, or cannot have its .d.ts files generated via --declaration
• If this is for an NPM package, match the name. If not, do not conflict with the name of an NPM package.
• Create it with dts-gen --dt, not by basing it on an existing project.
• Represents shape of module/library correctly
• tslint.json should be present and it shouldn't have any additional or disabling of rules. Just content as { "extends": "dtslint/dt.json" }. If for reason the some rule need to be disabled, disable it for that line using // tslint:disable-next-line [ruleName] and not for whole package so that the need for disabling can be reviewed.
• tsconfig.json should have noImplicitAny, noImplicitThis, strictNullChecks, and strictFunctionTypes set to true.

If changing an existing definition:

• Provide a URL to documentation or source code which provides context for the suggested changes: <>
• If this PR brings the type definitions up to date with a new version of the JS library, update the version number in the header.
• If you are making substantial changes, consider adding a tslint.json containing { "extends": "dtslint/dt.json" }. If for reason the any rule need to be disabled, disable it for that line using // tslint:disable-next-line [ruleName] and not for whole package so that the need for disabling can be reviewed.

If removing a declaration:

• If a package was never on DefinitelyTyped, you don't need to do anything. (If you wrote a package and provided types, you don't need to register it with us.)
• Delete the package's directory.
• Add it to notNeededPackages.json.