Bug 1072757 - Implement SettingsCore, BaseModule, Service Registration System
Merge pull request #24424 from alivedise/bugzilla/1072757/settings-service-core

Bug 1072757 - Implement SettingsCore, r=etienne
Bug 1080348 - Failing TC Gu test: keyboard-test/unit/mock_navigator_input_method_test.js