Pass reqExp option to interpolateName method

[vstukanov]

Add ability to generate dynamic bundle name according to required file path

Example:

module: {
  loaders: [
    { 
      test: /bundle\.js$/, 
      loader: 'bundle',
      query: { 
        lazy: true, 
        name: "[1]",
        regExp: "([\\w\\.]+)\\/[\\w\\.]+$"
      }
    }
  ]
}

[sokra]

Thanks