Started migrating the app menu back to the main nib file.

It turns out, nib files for NSMenus are easier to maintain than dozens lines of code.
Enabled code signing only for release builds.
Added a new Sleep Wake Timer class that will manage the caffeinate NSTask.
Refactored the sleep wake controller into an app controller and sleep wake timer.
Implemented Notifications and integrated the activation timer into the menu.
Notifications can be disabled via user defaults.
Display the scheduled time as first menu item (if available)
Prepared version, README and CHANGELOG for 1.2beta1
Added a menu item for "Indefinitely"
Updated the app name in various places…

I prefer the name KeepingYouAwake as a single word without spaces now.
Replaced NSDateFormatter with the shiny new NSDateComponentsFormatter.

It was hard to find this gem, because there is no documentation for it yet.