Couch views should support CommonJS modules

[norcal82]

Users should be able to add filename.lib.coffee files to the db/designs folder and have them imported as views are. This will give users the ability to put JS code in modules and keep our views DRY

https://wiki.apache.org/couchdb/CommonJS_Modules

views: {
      lib: { 
        module_name: "exports.bar = 42;" 
}