Fixed issue with relative path to signing.gradle in OSX
Let login form also respond to "done" IME action

By default the form only response to the login action and "null" IME action, but some keyboards (e.g. SwiftKey) supply the "done" action instead.
Set dark gray background for PagerTabStrip in week overview
Use fancy getBestDateTimePattern to get nice localized format for dates in overview activities
Fixed lint warnings about the default locale

Use Locale.US for date formatting, instead of implicitly relying on the default locale.