webpack loader api fixes

this.async() switches to async mode.
this.resourcePath is this.resource without query string.
module.exports.seperable doesn't exist anymore.
Use in combination with the css-loader

This will process url(...)s.
Use in combination with the css-loader

This will process url(...)s.
No need for "include css", the css-loader will do this more efficient
added tests
added config info again
added todo
Merge pull request #1 from sokra/with-css-loader

With css loader