fix: after restarting service by system, chargingOn option is not working
fix context issues

broadcastreceiver's context can't be used to register another
broadcastreceiver.
Add sleep time settings
add more sleep time handling in Service. Optimize icons, and change logo to high resolution one.
remove unnecessary jar files. update preferencecategory color. minimize strings
update prefrencecategory color. change version number