Implement Brackets Update-in-place via Installer

Removes "Sprint" suffix from the Brackets application name in support of updating future releases in-place (as opposed to installing into separate folders).
See Trello [user story](https://trello.com/c/xxabXFIG/1017-2-brackets-update-in-place-via-installer).
Also requires associated Brackets-shell [Pull Request #370](https://github.com/adobe/brackets-shell/pull/370).