svg with viewBox attribute results in clipped image.

[cjb06776]

Fix clipped images when svg specifies a viewbox attribute, as reported in #43

Also includes fix for incorrect handling of width attribute when the value is percent that was suggested in #42

[exupero]

1. Would you create an HTML file with a simple example that reproduces this problem so we can verify future changes don't break it? index.html has several different scenarios, if that helps. Don't worry about integrating with index.html; that can be done later.
2. It looks like you've only addressed width and not height.
3. Currently, the fallback values of width (box.width, clone.style.width, etc.) are parsed to integers, but these changes parse only the clone's explicit width. I don't see any reason parsing to an int should be necessary. Can you confirm?

[exupero]

Also, check the current index.html in a browser to make sure these changes don't cause any regressions compared to http://exupero.org/saveSvgAsPng/

[cjb06776]

1. I created a sample - viewboxtest.html. It is mostly self contained, but I wasn't able to completely reduce it to a trivial example (it uses d3 and an angular directive to create the svg, which is similar to how my app does things and how I was able to reproduce it). Example below of the problem occurring without and with the fix:
   
2. Yeah, you are right. I took your suggested snippet as is, and didn't look at it closer - expanded it to include height as well.
3. The styles do appear to need parseInt still in my tests. box.[width | height] doesn't from my observations, but the getComputedStyle method I see does return things in the form of "123px" for example. I've corrected this.
4. I checked index.html, and it looks like it is working as expected.

[exupero]

Looks good. One last question: did you find that box.width and box.height are already integers?

[cjb06776]

Looks good. One last question: did you find that box.width and box.height are already integers?

Yes.