- additional: Typescript-Interfaces for off() functions updated

This can be a breaking change. But it will also fix the contract of the method.

Add zoom():number to d.ts to get current zoom level

zoom should return `this`

We need this to be able to pass strings like "top-right" or "center" as transform origin on TypeScript, as they're already supported on JavaScript.

@neomorfeo

We need this to be able to define styles on the SVG from TypeScript.

@neomorfeo

Add attribute `rotate` to `MatrixTransformParam`

Implementing ElementAlias doesnt work because method definitions clash

CSSStyleDeclaration contains readonly rule, so I excluded them, otherwise it doesn't make sense
I didn't touch the Runner `css()` because I don't know the exact behavior of it.

The ease method on the runner takes the same constructor strings as the Ease class, so you can do things like element.animate(1000).ease('-').rotate(360).loop() 
Currently typescript throws an error saying that ease only accepts a Function as an argument.

1. Added the type information for `ScheduledRunnerInfo`, and updated the Timeline types to include it as a retuen type for `schedule`

2. Added a new function to Timeline, `getSchedule`, that simply returns the runner list. This seems to be cleaner than having the original `schedule` that can return two wildly different things.

I didn't remove the old functionality.

 - fixed `parent()` which correctly returns null if direct parent is the document or a document-fragment
 - fixed `add()` which correctly removes namespaces of non-root svg elements now when added to another svg element (#1086)
 - fixed `isRoot()` which correctly returns false, if the element is in a document-fragment

### Fixed
 - fixed `zoom()` method of runner which was passed a wrong parameter
 - fixed positioning methods of `TSpan` to position them by its bounding box
 - fixed `flip()` method which flips correctly by center by default now and accepts correct arguments
 - fixed a case in `rbox()` where not always all values of the box were updated
 - fixed `getOrigin()` function used by `transform()` so that all origin (#1085) popssibilities specified in the docs are working
 - fixed positioning of text by its baseline when using `amove()`
 - fixed tons of typings in the svg.d.ts file

### Added
 - added second Parameter to `SVG(el, isHTML)` which allows to explicitely create elements in the HTML namespace (#1058)
 - added `unlink()` and `linker()` to hyperlinked elements to remove or access the underling `<a>` element
 - added `wrap()` method to `Dom` which lets you wrap an element by another one
 - added `orient()` method to `Marker`
 - added `options` parameter to `dispatch()` and `fire()` to allow for more special needs
 - added `newLine()` constructor to `Text` to create a tspan marked as new line (#1088)
 - added lots of tests in es6 format

Big kudos to @kabentley for fixing the d.ts file