Import current LocaleManager.java.
Import current Fennec code.
Bug 1109000 - Part 1: move and extend LocaleAware.java -> Locales.java.
Bug 1109000 - Part 2: stub out getFallbackLocaleTag.
Bug 1109000 - Split statics out of BrowserLocaleManager. r=nalexander
Bug 947018: Delete large amounts of database migration code. r=wesj