* change drawer items

* rename SettingsActivity

* introduce AccountSettings activity

* improve account settings, move notification settings

* sync settings with server

* rename settings back to preferences

* add functionality for settings

* move mediaPreviewEnabled preference to AccountPreferences

* replace shared prefs with accountmanager

* move PreferencesFragment to support library

* split preferences fragment into smaller fragments,
merge AccountPreferencesActivity into PreferencesFragment

* adjust icon size, add icons to general preferences

* change mediaPreviewEnabled and alwaysShowSensitiveMedia pref position

* add database migration

* remove pullNotificationCheckInterval option

* fix  preference in TimelineFragment

* Update Chinese translations. (#915)

* Update zh-CN translations.

* Update zh-SG translations.

* Update zh-TW translations.

* Update zh-MO translations.

* Update zh-HK translations.

* Fix errors in zh-CN translations.

* Fix errors in zh-SG translations.

* Fix errors in zh-TW translations.

* Fix errors in zh-MO translations.

* Fix errors in zh-HK translations.