Add ZeroNet merger site feature

[jaros1]

Best option for integration between Money-Network and Money-Network wallets. Money-Network will have hubs with user data and hubs with wallets. Communication between hubs with dbQuery, files and file events.

[jaros1]

Add more data validation to JS code. Data in a merger site setup is created from several independent sites and can be invalid for many different reasons.

• validate data in all fileGet operations
• validate data before all fileWrite operations.
• make dbQuery selects and result processing more error robust.
• data quality should be checked on hub level. Data from hubs with bad data quality should not be used at all. This is not correct. Merger permission gives write permission to all hubs. But a logged user will only destroy his own data. A hub owner can destroy data for many users on this hub.
• allow users to blacklist bad data hubs? Black list hub was introduced in version 0.5.5. Not yet in ZeroNet API reference. List with hubs and data quality. Allow users to disable/blacklist hubs with bad data.

[jaros1]

Created issues for data

• quality should be checked on hub level. Data from hubs with bad data quality should not be used at all. This is not correct. Merger permission gives write permission to all hubs. But a logged user will only destroy his own data. A hub owner can destroy data for many users on this hub.
• allow users to blacklist bad data hubs? Black list hub was introduced in version 0.5.5. Not yet in ZeroNet API reference. List with hubs and data quality. Allow users to disable/blacklist hubs with bad data.