jakesgordon/sprite-factory — pull request #36 by phallstrom (2014-07-01 20:18:39+00:00)
Title: Use system instead of backticks for pngcrush so file names with spaces a...

...re properly escaped.

If the path the images are contained in contained a space, pngcrush would return an error that it couldn't find the file.

```
$ find foo\ bar
foo bar
foo bar/ph.png
```

```
$ sf foo\ bar --pngcrush --library chunkypng

Creating a sprite from following images:

foo bar/ph.png (269x397)

Output files:
foo bar.png
foo bar.css

Output size:
269x397

Could not find file: foo
Could not find file: bar.png
Could not find file: foo
Could not find file: bar.png.crushed
No such file or directory - foo bar.png.crushed
```