Zoom factor reset to current zoom level after calling `resize()`

[enspritz]

Maybe I'm using it wrong, but...

Reproduction steps:

1. i.e. bring up a demo tiger SVG image.
2. With you input devices, zoom in on the tiger to something definitely > 1x. Also, before or after, manipulate the DOM container of the tiger SVG to change its width/height.
3. At the JS console, effect the resize:

svgPanZoom.resize()

4. Attempt to zoom out. Turns out that the current zoom level seems to in effect be reset to 1x, and you can now zoom in and out as though starting fresh, except on a zoomed-in image.

In particular, the user is now able to zoom beyond configured maxZoom. This might also be the case for minZoom.

[enspritz]

My current workaround is to call .resetZoom() prior to .resize(). This will surprise users, but is less surprising than not being able zoom back to 1x after a resize event, such as by simply rotating their device.