Settings reorganization and cleanup Phase 1

-- Remove System header under Eos category
-- Move Weather as a new header under System category (still needs icon)
-- Move power menu to Developer options
-- Disable battery warnings now a checkable menu item in Battery settings

PS2: Remove unused xml and fix whitespace

PS3: Bring in weather icon thanks Daniel!

Change-Id: Iccd28bf1de198a1e7283b40f041b37f2441e908a