GitLab

 - DataSource renamed to DatabaseConnection
 - exception now prints missing parameter name
 - description updated
 - unnecessary this removed

 - code refactoring after last commit, clean-up, compilation fixes
 - Makefile updates
 - Added new unit-tests for DataSource (mostly moved from LeaseMgr
   unit-tests)

Also, moved alloc-engine specific messages to separate files.

Move lease_stats.h to leae_file_stats.h

Move logging init code into its own function.

Complete the current working on using the basic logging system
for messages from LFC

Add lease_stats to provide a class to gather statistics
about reading and writing leases to files.  Currently this
is used by the CSV file code and output by LFC.  The
information counted is: number of attempts, number of leases
and number of errors generated during reads and writes.

The interface-config map will hold the "interfaces" list which used to
be a global parameter. The new configuration layout is incompatible with
a previous layout.

Introduced a couple of new log messages and improved unit tests.

Also added an utility class to bulk load leases from the file.

 - Moved MAC operations to a new CfgMACSource class
 - Moved macros to HWaddr class
 - Added several unit-tests for MAC sources
 - MAC extraction code moved to separate function in Dhcpv6Srv

This change affects many files using the Configuration object and types
derived from it.