main layout: Relative -> Linear
chat layout: remove unneeded RelativeLayout
symlink locales as defined in Android's java.util.Locale
version.xml refactoring: add git revision into package_version
bump SDK to r17, include auto-RTL support

This change adds "start" and "end" properties to match existing "left"
and "right" values, to allow layout mirroring on Right-to-Left devices.

Automatic layout mirroring is supported as of Android SDK r17.
translations import from launchpad.net 2014-01-15