Revert build system from Gulp to Brunch
Merge branch 'master' of https://github.com/cozy/cozy-emails

Conflicts:
	client/app/components/email-list.coffee
	client/app/libs/PanelRouter.coffee
	client/app/stores/EmailStore.coffee
	client/app/stores/ImapFolderStore.coffee
	client/app/stores/MailboxStore.coffee
	client/app/utils/XHRUtils.coffee
Update build documentation
Merge pull request #9 from clochix/master

Revert build system from Gulp to Brunch