Release 2.5.0

Release 2.5.0

### Added
- added a plot and array method to `SVG.TextPath` (#582)
- added `clone()` method to `SVG.Array/PointArray/PathArray` (#590)
- added `font()` method to `SVG.Tspan`
- added `SVG.Box()`
- added `transform()` method to boxes
- added `event()` to `SVG.Element` to retrieve the event that was fired last on the element (#550)

### Changed
- changed CHANGELOG to follow the conventions described in [“Keep a CHANGELOG”](http://keepachangelog.com) (#578)
- make the method plot a getter when no parameter is passed for `SVG.Polyline`,`SVG.Polygon`, `SVG.Line`, `SVG.Path` (related #547)
- allow `SVG.PointArray` to be passed flat array
- change the regexp `SVG.PointArray` use to parse string to allow more flexibility in the way spaces and commas can be used
- allow `plot` to be called with 4 parameters when animating an `SVG.Line`
- relative value for `SVG.Number` are now calculated in its `morph` method (related #547)
- clean up the implementation of the `initAnimation` method of the FX module (#547, #552, #584)
- deprecated `.tbox()`. `.tbox()` now map to `.rbox()`. If you are using `.tbox()`, you can substitute it with `.rbox()` (#594, #602)
- all boxes now accept 4 values or an object on creation
- `el.rbox()` now always returns the right boxes in screen coordinates and has an additional paramater to transform the box into other coordinate systems
- `font()` method can now be used like `attr()` method (#620)
- events are now cancelable by default (#550)

### Fixed
- fixed a bug in the plain morphing part of `SVG.MorphObj` that is in the FX module
- fixed bug which produces an error when removing an event from a node which was formerly removed with a global `off()` (#518)
- fixed a bug in `size()` for poly elements when their height/width is zero (#505)
- viewbox now also accepts strings and arrays as constructor arguments
- `SVG.Array` now accepts a comma seperated string and returns array of numbers instead of strings
- `SVG.Matrix` now accepts an array as input
- `SVG.Element.matrix()` now accepts also 6 values
- `dx()/dy()` now accepts percentage values, too but only if the value on the element is already percentage
- `flip()` now flips on both axis when no parameter is passed
- fixed bug with `documentElement.contains()` in IE
- fixed offset produced by svg parser (#553)
- fixed a bug with clone which didnt copy over dom data (#621)