This resolves #245, #315, #344, #351, #355 and is related to #281, #358

#315
- Cloud-setting is menu is added
- Check-box is used to allow sync over cellular network
- By default, wifi will be always used first when automatic-sync is enabled
- Instead of periodic/booting sync, sync happens when network-connectivity changes and application starts
- automatic sync will happen with all registered google accounts

#344 
- SharedPreferences is used to log and track the successful backup files 
- This logging happens when app is firstly installed, manual sync button is pressed and new file is created in aikuma

#351 
- Now only the last recording is preserved

#355 
- Valid gesture is increased a little from 100msec to 250msec  

#245 
- Item search using language code is now supported by CloudSearchActivity

#281 #358 
- Part of aikuma status is now shown (Used/Available storage, number of users/items, Cloud backup ratio)