Enhancement: newer version of node-imagemagick

[cramhead]

I ran into a number of problems with this package. I tracked it down to problems the node-imagemagick package. Since it's not maintained I decided to give it a bit of love.

The interface is exactly the same, but there are a number of fixes and improvements via jslint and jshint. I posted the package to npmjs.org under the name imagemagick-a-la-node, i.e. https://npmjs.org/package/imagemagick-a-la-node, source at https://github.com/cramhead/node-imagemagick. I've been running it for about a month and have not found any problems. Please feel free to use it and if you have any problems I'd be happy to see if I can get things sorted or accept pull requests.