Work on #20
Simplify _getIndentSize() function
Also extract SVG width/height attributes
Should be #20

* New method of checking if the image is supported or not,
* Simplify some code
* Fixed displaying of "width" and "height" for unsupported images

All this comes at the cost of a complete lack of SVG support. That's
fine, though. I can write a separate routine to handle that, all while
improving width/height detection accuracy via src/SvgSize. :smiley:
Merge pull request #23 from le717/issue-20

Properly detect non-SVG image size