* Fix redeclared variable (mdaines#160)

* Fix redeclared variable (mdaines#160)

* Add support for -n (Nop) option (mdaines#151)

* Specify --libdir option (mdaines#153)
* Correctly forward errors not derived from Error (mdaines#145)

* Viz.js now has first-class support for Web Workers, and returns Pro…

…mises for all rendering functions, rather than accepting callbacks for some of its utility functions. However, you don't have to use Web Workers: Viz.js still works with just script tags.

* API and rendering code have been split into separate files to make it easier to work with Viz.js in bundlers.
* New output types: JSON objects and SVG elements. For example, the renderSVGElement function returns the promise of an SVGSVGElement object, ready to insert into the document.
* The single Viz() function is now a class and reuses its Emscripten module instance, improving performance across multiple calls.
* The API code is now built with Rollup, and the release includes an ES6 module.
* Added yInvert option. (Equivalent to the -y command-line option.)
* TypeScript declarations have been removed in this release.

* Use ".render.js" suffix instead of ".js.opaque".

* Accept a Worker instance for the worker option instead of a string. Add workerURL option for passing the URL of a worker as a string. Less specific detection of worker scope.

* Make sure the Emscripten module isn't exported when Viz.js is loade…

…d in an AMD environment. (mdaines#130)

* Remove TypeScript declarations.

* Build with Rollup.
* Include ES6 module in npm release.

* Fix TypeScript declarations.

* Free layout and graph when we're done with them. Reuse the Emscript…

…en module instance.

* Export the Module and render functions from rendering script files.
* Use ".js.opaque" rendering script files instead of ".module".

* Don't wait for onload to resolve image elements.