Prevents cloning the Configuration object, and therefore reduces the possibility of creating
more than one object - we are avoiding such situations, becouse Configuration is implementing
Singleton design pattern
This class is a Singleton, which purpose is to manage system's configuration data such as:
authorization data of users allowed to use the system,
configured connections to databases
Data is passed to/from a subclass of ConfigurationIO class, which gives great flexibility in choose of
configuration data storage place and access methods.
This is an implementation of ConfigurationIO abstract class, which is ment to be use for accessing configuration
data stored in file on local filesystem.
Returns a DatabaseConnector used to download table data after the dump is
created, if the dump is set in "read from database" mode (by calling
setDatabaseReader()).
Returns a stream which can be used to read records of table data from a backup
file, if the dump is set in "read from file" mode (by calling setFileReader()).
Implementations of this abstract method should cover all logic for reading data from it's storage place,
and provide access to it through an InputStream object.
Implementations of this abstract method should cover all logic for writing data to it's storage place,
and provide access to it through an OutputStream object.