Implemented basic options support for compressor and comments. 

Hi, 
for the minify() node.js util I just implemented basic options support for compressor and comments.


Example use:
var result = UglifyJS.minify([files...], {
	compressor: {
		warnings:false
	},
	// https://github.com/mishoo/UglifyJS2#keeping-copyright-notices-or-other-comments
	comments:true  // false, true or "all"
});

For compatibility, the warnings boolean can still be in options like this:
var result = UglifyJS.minify([files...], {
	warnings:true
});

Cheers
- Johnny