Sync single and unified mailboxes efficiently

js/app.js

js/controller/foldercontroller.js

js/models/account.js

js/service/accountservice.js

js/service/foldersyncservice.js

js/service/messageservice.js

js/tests/service/foldersyncservice_spec.js

js/tests/test-main.js

js/views/composerview.js

js/views/messagesview.js

karma.conf.js

package.json