Task targets, files and options may be specified according to the grunt [Configuring tasks](http://gruntjs.com/configuring-tasks) guide.

Minify images using [OptiPNG](http://optipng.sourceforge.net) and [jpegtran](http://jpegclub.org/jpegtran/).
Task targets, files and options may be specified according to the grunt [Configuring tasks](http://gruntjs.com/configuring-tasks) guide.

Minify images using [OptiPNG](http://optipng.sourceforge.net) and [jpegtran](http://jpegclub.org/jpegtran/).

Images will be cached and only minified again if they change.

Update readme about caching of images
Update readme about caching of images
