panning on mobile browser sometimes locks into strictly vertical or horizontal panning

[GoogleCodeExporter]

What steps will reproduce the problem?
1. open embedded svg in mobile safari or chrome.

What is the expected output? What do you see instead?

Click and drag in any direction is expected.

Scrolling/ panning with finger on mobile Safari browser sometimes locks into 
vertical or horizontal panning. On the desktop browser this does not happen 
with click and drag.

What version of the product are you using? On what operating system?
SVGPan 1.2.2
iOS 6.1.3 mobile safari and mobile chrome


Please provide any additional information below.
Three files attached which are used to recreate the issue. 
It seems like it might have something to do with touch on mobile, as both 
safari and chrome on iPad have the same issue.

Original issue reported on code.google.com by [email protected] on 14 Aug 2013 at 9:56

Attachments:

• test.html
• svgRinkOlympic.svg
• SVGPan.js