Added Version28 migration.
Streamlined OrmPreference a bit + made use of in PersistenceManager.
Scrapped idea of DB preferences due to android mechanisms.
Implemented AndroidSharable for anything btw activities.
Made ContextUtils.
PreferenceNode.sub() now returns itself for ns == null.
Made utils.migration.IMigration*, abstraction from persist.migration.*
Refactored persist.migration.* using utils.migration.*
Fixed a bug in IMigrationExecutor.
Made the new preference module.
Improved ChallengeGlobalPreferences.
Made use of new preference system.
Also made changes in XML.
shortened stuff a bit.
GPSFilterAreaAdapter now uses ViewHolder.
fixed on-fail logic for UpgradeExecutor.
Added logic for SortMode in prefs.
Fixed bug in SharedPreferenceManager.