Use correct path to import file
Replace deprecated `import_dxf` call with `import`

Recommended when rendering in OpenSCAD.
Remove whitespace at EOL
Remove commented code
Use consistent indentation

The original indentation was two spaces in most places, but with some lines indented with a tab (and sometimes both). Converting this tab to spaces only fit the rest of the indentation if it was six(!) spaces wide.
Merge pull request #7 from l0b0/gh-pages

OpenSCAD logo fixes and cleanup